作者机构：
[Wang, Yao; Zheng, Yong; Wang, Na-Na; Chen, Yi-Hao; Zhou, Li; Lu, Rui; Li, Xue-Bao; Li, Yang] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.;[Wang, Na-Na] Anhui Agr Univ, Sch Life Sci, Hefei 230036, Peoples R China.
通讯机构：
[Yong Zheng; Xue-Bao Li] H;Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University , Wuhan 430079, China
摘要：
Cotton, one of the most important crops in the world, produces natural fiber materials for the textile industry. WRKY transcription factors play important roles in plant development and stress responses. However, little is known about whether and how WRKY transcription factors regulate fiber development of cotton so far. In this study, we show that a fiber-preferential WRKY transcription factor, GhWRKY16, positively regulates fiber initiation and elongation. GhWRKY16-silenced transgenic cotton displayed a remarkably reduced number of fiber protrusions on the ovule and shorter fibers compared to the wild-type. During early fiber development, GhWRKY16 directly binds to the promoters of GhHOX3, GhMYB109, GhCesA6D-D11, and GhMYB25 to induce their expression, thereby promoting fiber initiation and elongation. Moreover, GhWRKY16 is phosphorylated by the mitogen-activated protein kinase GhMPK3-1 at residues T-130 and S-260. Phosphorylated GhWRKY16 directly activates the transcription of GhMYB25, GhHOX3, GhMYB109, and GhCesA6D-D11 for early fiber development. Thus, our data demonstrate that GhWRKY16 plays a crucial role in fiber initiation and elongation, and that GhWRKY16 phosphorylation by GhMPK3-1 is essential for the transcriptional activation on downstream genes during the fiber development of cotton.
摘要：
Acetylation and deacetylation of histones are important for regulating a series of biological processes in plants. Histone deacetylases (HDACs) control the histone deacetylation that plays an important role in plant response to abiotic stress. In our study, we show the evidence that GhHDT4D (a member of the HD2 subfamily of HDACs) is involved in cotton (Gossypium hirsutum) response to drought stress. Overexpression of GhHDT4D in Arabidopsis increased plant tolerance to drought, whereas silencing GhHDT4D in cotton resulted in plant sensitivity to drought. Simultaneously, the H3K9 acetylation level was altered in the GhHDT4D silenced cotton, compared with the controls. Further study revealed that GhHDT4D suppressed the transcription of GhWRKY33, which plays a negative role in cotton defense to drought, by reducing its H3K9 acetylation level. The expressions of the stress-related genes, such as GhDREB2A, GhDREB2C, GhSOS2, GhRD20-1, GhRD20-2 and GhRD29A, were significantly decreased in the GhHDT4D silenced cotton, but increased in the GhWRKY33 silenced cotton. Given these data together, our findings suggested that GhHDT4D may enhance drought tolerance by suppressing the expression of GhWRKY33, thereby activating the downstream drought response genes in cotton.
作者机构：
[Zheng, Yong; Chen, Yi-Hao; Wang, Na-Na; Zhang, Jing-Bo; Li, Xue-Bao] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
通讯机构：
[Li, Xue-Bao] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
关键词：
Cotton (gossypium hirsutum);Mitogen-activated protein kinase (MAPK);Fiber elongation;Phosphorylation;Phytohormone signaling
摘要：
Key message 56 MAPK genes were identified in upland cotton genome, and unequally distribute on 22 chromosomes of cotton genome. They can be divided into 4 groups, and the TEY type of T-loop exists in A, B and C groups, but the TDY type of T-loop is only in group D. Furthermore, GhMPK6 may be involved in phosphorylation of its downstream proteins for regulating fiber elongation of cotton. Mitogen-activated protein kinases (MAPKs) are important in regulating plant development as well as stress response. In this study, we genome-widely identified 56 MAPK genes in upland cotton. These MAPK genes unequally distribute on 22 chromosomes of cotton genome, but no MAPK gene is located on At_Chr6, Dt_Chr6, At_Chr13 and Dt_Chr13. The exons and introns in GhMAPK gene family vary widely at the position, number and length. Furthermore, GhMAPK family can be divided into 4 groups (A, B, C and D), and the TEY type of T-loop exists in three groups (A, B and C), but the TDY type of T-loop is only in group D. Further study revealed that some GhMAPK genes (including GhMPK6) are preferentially expressed in elongating fibers. GhMPK6 maintains a high phosphorylation level in elongating fibers, and its phosphorylation was enhanced in fibers by phytohormones brassinosteroid (BR), ethylene and indole-3-acetic acid (IAA). Additionally, GhMPK6 could interact with GhMKK2-2 and GhMKK4, suggesting that GhMKK2-2/4-GhMPK6 module may be involved in phosphorylation of its downstream proteins for regulating fiber elongation of cotton.
摘要：
Mitogen-activated protein kinase kinase kinases (MAPKKKs) are significant components in the MAPK signal pathway and play essential roles in regulating plants against drought stress. To explore MAPKKK gene family functioning in cotton response and resistance to drought stress, we conducted a systematic analysis of GhMAPKKKs. In this study, 157 nonredundant GhMAPKKKs (including 87 RAFs, 46 MEKKs and 24 ZIKs) were identified in cotton (Gossypium hirsutum). These GhMAPKKK genes are unevenly distributed on 26 chromosomes, and segmental duplication is the major way for the enlargement of MAPKKK family. Furthermore, members within the same subfamily share a similar gene structure and motif composition. A lot of cis-elements relevant to plant growth and response to stresses are distributed in promoter regions of GhMAPKKKs. Additionally, these GhMAPKKKs show differential expression patterns in cotton tissues. The transcription levels of most genes were markedly altered in cotton under heat, cold and PEG treatments, while the expressions of some GhMAPKKKs were induced in cotton under drought stress. Among these drought-induced genes, we selected GhRAF4 and GhMEKK12 for further functional characterization by virus-induced gene silencing (VIGS) method. The experimental results indicated that the gene-silenced cotton displayed decreased tolerance to drought stress. Malondialdehyde (MDA) content was higher, but proline accumulation, relative leaf water content and activities of superoxide dismutase (SOD) and peroxidase (POD) were lower in the gene-silenced cotton, compared with those in the controls, under drought stress. Collectively, a systematic survey of gene structure, chromosomal location, motif composition and evolutionary relationship of MAPKKKs were performed in upland cotton (Gossypium hirsutum). The following expression and functional study showed that some of them take important parts in cotton drought tolerance. Thus, the data presented here may provide a foundation for further investigating the roles of GhMAPKKKs in cotton response and resistance to drought stress.
摘要：
<jats:title>Summary</jats:title><jats:p>
<jats:list list-type="bullet">
<jats:list-item><jats:p>Basic helix–loop–helix (bHLH) proteins are involved in transcriptional networks controlling a number of biological processes in plants. However, little information is known on the roles of bHLH proteins in cotton fibre development so far.</jats:p></jats:list-item>
<jats:list-item><jats:p>Here, we show that a cotton bHLH protein (GhFP1) positively regulates fibre elongation. <jats:italic>GhFP1</jats:italic> transgenic cotton and Arabidopsis plants were generated to study how GhFP1 regulates fibre cell elongation.</jats:p></jats:list-item>
<jats:list-item><jats:p>Fibre length of the transgenic cotton overexpressing <jats:italic>GhFP1</jats:italic> was significantly longer than that of wild‐type, whereas suppression of <jats:italic>GhFP1</jats:italic> expression hindered fibre elongation. Furthermore, overexpression of <jats:italic>GhFP1</jats:italic> in Arabidopsis promoted trichome development. Expression of the brassinosteroid (BR)‐related genes was markedly upregulated in fibres of <jats:italic>GhFP1</jats:italic> overexpression cotton, but downregulated in <jats:italic>GhFP1</jats:italic>‐silenced fibres. BR content in the transgenic fibres was significantly altered, relative to that in wild‐type. Moreover, GhFP1 protein could directly bind to the promoters of <jats:italic>GhDWF4</jats:italic> and <jats:italic>GhCPD</jats:italic> to activate expression of these BR‐related genes.</jats:p></jats:list-item>
<jats:list-item><jats:p>Therefore, our data suggest that GhFP1 as a positive regulator participates in controlling fibre elongation by activating BR biosynthesis and signalling. Additionally, homodimerisation of GhFP1 may be essential for its function, and interaction between GhFP1 and other cotton bHLH proteins may interfere with its DNA‐binding activity.</jats:p></jats:list-item>
</jats:list>
</jats:p>
作者机构：
[Wang, Yao; Wu, Yu-Wei; Wang, Na-Na; Lu, Rui; Li, Xue-Bao; Wang, Ya-Chao; Li, Yang] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.;[Li, Li] Univ Toronto, Hosp Sick Children, Arthur & Sonia Labatt Brain Tumor Res Ctr, Dept Genet & Genome Biol, Toronto, ON M5G 0A4, Canada.;[Li, Li] Univ Toronto, Toronto, ON M5G 0A4, Canada.
通讯机构：
[Li, Xue-Bao] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
摘要：
Spatiotemporally regulated callose deposition is an essential, genetically programmed phenomenon that promotes pollen development and functionality. Severe male infertility is associated with deficient callose biosynthesis, highlighting the significance of intact callose deposition in male gametogenesis. The molecular mechanism that regulates the crucial role of callose in production of functional male gametophytes remains completely unexplored. Here, we provide evidence that the gradual upregulation of a previously uncharacterized cotton (Gossypium hirsutum) pollen-specific SKS-like protein (PSP231), specifically at the post pollen-mitosis stage, activates callose biosynthesis to promote pollen maturation. Aberrant PSP231 expression levels caused by either silencing or overexpression resulted in late pollen developmental abnormalities and male infertility phenotypes in a dose-dependent manner, highlighting the importance of fine-tuned PSP231 expression. Mechanistic analyses revealed that PSP231 plays a central role in triggering and fine-tuning the callose synthesis and deposition required for pollen development. Specifically, PSP231 protein sequesters the cellular pool of RNA-binding protein GhRBPL1 to destabilize GhWRKY15 mRNAs, turning off GhWRKY15-mediated transcriptional repression of GhCalS4/GhCalS8 and thus activating callose biosynthesis in pollen. This study showed that PSP231 is a key molecular switch that activates the molecular circuit controlling callose deposition toward pollen maturation and functionality and thereby safeguards agricultural crops against male infertility.
作者机构：
[Li, Yang; Li, Xue-Bao; Wang, Na-Na; Zhou, Li; Xu, Shang-Wei; Sun, Yun-Lue; Liu, Dong] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Li, Y; Li, XB] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
摘要：
As the important source of natural fibers in the textile industry, cotton fiber quality and yield are often restricted to drought conditions because most of cotton plants in the world grow in the regions with water shortage. WRKY transcription factors regulate multiple plant physiological processes, including drought stress response. However, little is known of how the WRKY genes respond to drought stress in cotton. Our previous study revealed GhWRKY33 is leaf-specific and induced by drought stress. In this study, our data showed GhWRKY33 protein localizes to the cell nucleus and is able to bind to "W-box" cis-acting elements of the target promoters. Under drought stress, GhWRKY33 overexpressing transgenic Arabidopsis was withered much more quickly than wild type due to faster water loss. Moreover, GhWRKY33 transgenic plants displayed more tolerance to abscisic acid (ABA), relative to wild type. Expression of some drought stress-related genes and ABA-responsive genes were changed in the GhWRKY33 transgenic Arabidopsis with drought or ABA treatment. Collectively, our findings indicate that GhWRKY33 may act as a negative regulator to mediate plant response to drought stress and to participate in the ABA signaling pathway.
摘要：
Anther/pollen development is a highly programmed process in flowering plants. However, the molecular mechanism of regulating anther/pollen development is still largely unclear so far. Here, we report a cotton WRKY transcription factor (GhWRKY22) that functions in anther/pollen development. Quantitative RT-PCR and GUS activity analyses revealed that GhWRKY22 is predominantly expressed in the late developing anther/pollen of cotton. The transgenic Arabidopsis plants expressing GhWRKY22 displayed the male fertility defect with the fewer viable pollen grains. Expression of the genes involved in jasmonate (JA) biosynthesis was up-regulated, whereas expression of the JA-repressors (JAZ1 and JAZ8) was down-regulated in the transgenic Arabidopsis plants expressing GhWRKY22, compared with those in wild type. Yeast one-hybrid and ChIP-qPCR assays demonstrated that GhWRKY22 modulated the expression of JAZ genes by directly binding to their promoters for regulating anther/pollen development. Yeast two-hybrid assay indicated that GhMYB24 could interact with GhJAZ8-A and GhJAZ13-A. Furthermore, expression of AtMYB24, AtPAL2 and AtANS2 was enhanced in the transgenic Arabidopsis plants, owing to GhWRKY22 overexpression. Taking the data together, our results suggest that GhWRKY22 acts as a transcriptional repressor to regulate anther/pollen development possibly by modulating the expression of the JAZ genes.
摘要：
MYB proteins represent one of the largest transcription factor (TF) families in plants, some of which act as key transcriptional regulators of secondary cell wall (SCW) biosynthesis. Cotton (Gossypium hirsutum) fiber is thought to be an ideal single-cell model to study cell elongation and SCW biosynthesis. However, little knowledge regarding the TFs controlling fiber SCW biosynthesis, particularly for R2R3-MYBs is known. By far, no comprehensive genome-wide analysis of the secondary wall-associated R2R3-MYBs has been reported in cultivated tetraploid upland cotton. In this study, we identified 419 R2R3-MYB genes by systematically examining the cotton genome. A combination of phylogenetic, RNA-seq and co-expression analyses indicated that 36 R2R3-MYBs were either preferentially or highly expressed in 20 day post anthesis (dpa) fibers and are putative SCW regulators. Among these MYB genes, 22 MYBs are homologs of known SCW MYB proteins and the other 14 MYBs are novel proteins without prior reported SCW biosynthesis-related functions. Finally, we highlighted on the roles of two MYBs named GhMYB46_D13 and GhMYB46_D9, both of which displayed the highest expression in 20 dpa fibers. Expression of GhMYB46_D13 or GhMYB46_D9 individually in Arabidopsis resulted in ectopic SCW deposition in transgenic plants. Furthermore, both GhMYB46_D13 and GhMYB46_D9 were able to activate the cotton fiber SCW cellulose synthase gene promoters. Thus, we have identified 36 R2R3-MYBs as potential SCW regulators in cotton fibers that represent strong candidates for further functional studies during fiber development and SCW thickening.
作者机构：
[Wang, Huan; Jia, Han-Xin; Zheng, Yong; Ren, Feng; Li, Xue-Bao; Wei, Ying-Li; Zha, Lei; Huang, Ke-Lin] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Ren, F; Li, XB] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
关键词：
Abscisic acid (ABA), gibberellin (GA);Brassica napus;Phosphate (pi);Phosphorus (P);Seed germination;Seedling growth and development
摘要：
BACKGROUND: Seed germination and seedling establishment are two of the most critical phases in plant development. However, the molecular mechanisms underlying the effect of phosphorus on seed germination and post-germinated growth of oilseed rape are unclear so far. Here, we report the role of BnPHT1;4 in seed germination and early seedling development of Brassica napus. RESULTS: Our results show that BnPHT1;4 is preferentially expressed in cotyledons of early developing seedlings. Overexpression of BnPHT1;4 in oilseed rape promoted seed germination and seedling growth. Expression levels of the genes related to ABA and GA biosynthesis and signaling were significantly altered in BnPHT1;4 transgenic seedlings. Consequently, active GA level was up-regulated, whereas ABA content was down-regulated in BnPHT1;4 transgenic seedlings. Furthermore, exogenous GA could promote seed germination of wild type, while exogenous ABA could partially recover the advanced-germination phenotype of BnPHT1;4 transgenic seeds. Total phosphorus content in cotyledons of the transgenic seedlings was decreased more rapidly than that in wild type when Pi was supplied or deficient, and Pi contents in shoots and roots of the BnPHT1;4 transgenic plants were higher than those in wild type under high and low Pi conditions. CONCLUSIONS: Our data suggest that the high-affinity transporter BnPHT1;4 is involved in phosphorus acquisition and mobilization for facilitating seed germination and seedling growth of Brassica napus by modulating ABA and GA biosynthesis.
通讯机构：
[Li, DD; Huang, GQ] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
关键词：
Abscisic acid (ABA);Ethylene;GhEIN3;Gossypium hirsutum;Reactive oxygen species (ROS);Salt stress
摘要：
Ethylene insensitive 3 (EIN3), a key transcription factor in ethylene signal transduction, play important roles in plant stress signaling pathways. In this study, we isolated and characterized an EIN3-like gene from cotton (Gossypium hirsutum), designated as GhEIN3. GhEIN3 is highly expressed in vegetative tissues, and its expression is induced by 1-aminocyclopropane-1-carboxylic acid (ACC) and NaCl. Ectopic expression of GhEIN3 in Arabidopsis elevated plants' response to ethylene, which exhibit smaller leaves, more root hairs, shorter roots and hypocotyls. The germination rate, survival rate and root length of GhEIN3 transgenic plants were significantly improved compared to wild type under salt stress. GhEIN3 transgenic plants accumulated less H2O2 and malondialdehyde (MDA), while higher superoxide dismutase (SOD) and peroxidase (POD) activities were detected under salt stress. In addition, expression of several genes related to reactive oxygen species (ROS) pathway and ABA signaling pathway was increased in the GhEIN3 transgenic plants under salt stress. In contrast, virus-induced gene silencing (VIGS) of GhEIN3 in cotton enhanced the sensitivity of transgenic plants to salt stress, accumulating higher H2O2 and MDA and lower SOD and POD activities compared to control plants. Collectively, our results revealed that GhEIN3 might be involved in the regulation of plant response to salt stress by regulating ABA and ROS pathway during plant growth and development.
作者机构：
[Zhao, Cai-Zhi; Jia, Han-Xin; Zhang, Mei-Li; Xiong, Huan; Wu, Huan; Li, Xue-Bao; Huang, Ke-Lin; Liu, Chun-Sen; Ren, Feng; Ma, Guang-Jing] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.;[Chen, Liang] Chinese Acad Sci, Key Lab Plant Germplasm Enhancement & Specialty A, Wuhan 430074, Hubei, Peoples R China.;[Chen, Liang] Chinese Acad Sci, Wuhan Bot Garden, Wuhan 430074, Hubei, Peoples R China.;[Kjorven, Johan Olav] Cornell Univ, Dept Microbiol, Ithaca, NY 14853 USA.
通讯机构：
[Ren, Feng] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
摘要：
PHOSPHATE STARVATION RESPONSE1 (PHR1) is a key regulatory component of the response to phosphate (Pi) starvation. However, the regulation of PHR1 in this response remains poorly understood. Here, we report that PHR1 is a target of the transcription factors AUXIN RESPONSE FACTOR7 (ARF7) and ARF19 and is positively regulated by auxin signaling in Arabidopsis (Arabidopsis thaliana) roots. PHR1 expression was induced by exogenous auxin and suppressed by auxin transport inhibitors in Arabidopsis roots. In the PHR1 promoter, three auxin-response elements, which are bound directly by ARF7 and ARF19, were shown to be essential for PHR1 expression. The aril, arf19, and aril arf19 mutants showed down-regulated expression of PHR1 and downstream Pi starvation-induced genes in roots; they also exhibited defective Pi uptake in roots and overaccumulation of anthocyanin in shoots. The induction of lateral root formation in response to low Pi and to exogenous auxin was decreased in the phr1 mutant, whereas the expression of LATERAL ORGAN BOUNDARIES-DOMAIN16 (LBD16) and LBD29 was not changed significantly. PHR1 acted independently of LBD16 and LBD29 in the regulation of lateral root formation in response to low Pi. Under low-Pi conditions, lateral root impairment in the arf7 arf19 mutant was partially rescued by constitutive expression of PHR1, demonstrating that reduced PHR1 expression contributed to the arf7 arf19 phenotype. In addition to PHR1, other genes encoding MYB-CC members also were targets of ARF7 and ARF19. Our work thus reveals a mechanism coordinating auxin signaling and the PHR1 regulon in Arabidopsis responses to Pi deficiency.
摘要：
Background: Basic helix-loop-helix/helix-loop-helix (bHLH/HLH) transcription factors play important roles in plant development. Many reports have suggested that bHLH/HLH proteins participate in brassinosteroid (BR) hormone signaling pathways to promote cell elongation. Cotton fibers are single-cells and derived from seed surface. To explore the roles of bHLH/HLH proteins in cotton fiber development progress by modulating BR signaling pathway, we performed a systematic analysis of the bHLH/HLH gene family in upland cotton (Gossypium hirsutum) genome. Results: In this study, we identified 437 bHLH/HLH genes in upland cotton (G. hirsutum) genome. Phylogenetic analysis revealed that GhbHLH/HLH proteins were split into twenty six clades in the tree. These GhbHLH/HLH genes are distributed unevenly in different chromosomes of cotton genome. Segmental duplication is the predominant gene duplication event and the major contributor for amplification of GhbHLH/HLH gene family. The GhbHLH/HLHs within the same group have conserved exon/intron pattern and their encoding proteins show conserved motif composition. Based on transcriptome data, we identified 77 GhbHLH/HLH candidates that are expressed at relatively high levels in cotton fibers. As adding exogenous BR (brassinolide, BL) or brassinazole (Brz, a BR biosynthesis inhibitor), expressions of these GhbHLH/HLH genes were up-regulated or down-regulated in cotton fibers. Furthermore, overexpression of GhbHLH282 (one of the BR-response genes) in Arabidopsis not only promoted the plant growth, but also changed plant response to BR signaling. Conclusion: Collectively, these data suggested that these GhbHLH/HLH genes may participate in BR signaling transduction during cotton fiber development. Thus, our results may provide a valuable reference data as the basis for further studying the roles of these bHLH/HLH genes in cotton fiber development.
摘要：
<jats:title>
<jats:bold>Summary</jats:bold>
</jats:title><jats:p><jats:styled-content style="fixed-case">LIM</jats:styled-content> domain proteins are cysteine‐rich proteins, and are often considered as actin bundlers and transcription factors in plants. However, the roles of <jats:styled-content style="fixed-case">XLIM</jats:styled-content> proteins in plants (especially in cotton) remain unexplored in detail so far. In this study, we identified a cotton <jats:styled-content style="fixed-case">XLIM</jats:styled-content> protein (Gh<jats:styled-content style="fixed-case">XLIM</jats:styled-content>6) that is preferentially expressed in cotton fiber during whole elongation stage and early secondary cell wall (<jats:styled-content style="fixed-case">SCW</jats:styled-content>) synthesis stage. The <jats:italic>Gh<jats:styled-content style="fixed-case">XLIM</jats:styled-content>6</jats:italic>‐silenced transgenic cotton produces shorter fibers with thinner cell walls, compared with wild‐type (WT). Gh<jats:styled-content style="fixed-case">XLIM</jats:styled-content>6 protein could directly bind F‐actin and promote actin polymerization both <jats:italic>invitro</jats:italic> and <jats:italic>invivo</jats:italic>. It also acts as a transcription factor to suppress <jats:italic>Gh<jats:styled-content style="fixed-case">KNL</jats:styled-content>1</jats:italic> expression through binding the <jats:italic><jats:styled-content style="fixed-case">PAL</jats:styled-content></jats:italic>‐box element of <jats:italic>Gh<jats:styled-content style="fixed-case">KNL</jats:styled-content>1</jats:italic> promoter, and subsequently regulate the expression of <jats:italic>CesA</jats:italic> genes related to cellulose biosynthesis and deposition in <jats:styled-content style="fixed-case">SCW</jats:styled-content>s of cotton fibers. The cellulose content in fibers of <jats:italic>Gh<jats:styled-content style="fixed-case">XLIM</jats:styled-content>6</jats:italic><jats:styled-content style="fixed-case">RNA</jats:styled-content>i cotton is lower than that in WT. Taken together, these data reveal the dual roles of Gh<jats:styled-content style="fixed-case">XLIM</jats:styled-content>6 in fiber development. On one hand, Gh<jats:styled-content style="fixed-case">XLIM</jats:styled-content>6 functions in fiber elongation through binding to F‐actin to maintain the dynamic F‐actin cytoskeleton. On the other hand, Gh<jats:styled-content style="fixed-case">XLIM</jats:styled-content>6 fine‐tunes fiber <jats:styled-content style="fixed-case">SCW</jats:styled-content> formation, probably through directly suppressing transcription of <jats:italic>Gh<jats:styled-content style="fixed-case">KNL</jats:styled-content>1</jats:italic> to promote cellulose biosynthesis.</jats:p>
摘要：
Jasmonate ZIM-domain (JAZ) proteins and DELLA proteins are key negative regulators of jasmonates (JAs) and gibberellin (GA) signaling, respectively. In this study, we found JA and GA synergistically promote fiber cell initiation. We characterized the cellular function of a JAZ protein (GhJAZ3), and a DELLA protein (GhSLR1) of cotton (Gossypium hirsutum). GhJAZ3 is specifically expressed in elongating fibers, while GhSLR1 is expressed in different tissues and at a relatively higher level in 3 DPA ovules. GhSLR1 and GhJAZ3 proteins are localized in the cell nucleus. Yeast two-hybrid analysis indicated that GhSLR1, GhJAZ3 and GhDEL65 could interact with each other, and GhSLR1 could also interact with GhBZR1. Overexpression of GhJAZ3 in Arabidopsis increased hypocotyl and root length, leaf trichome length, and plant height, but decreased the number of leaf trichome, while overexpression of GhSLR1 in Arabidopsis decreased hypocotyl length, leaf trichome length and density. Expression of several leaf trichome initiation determinators (GL3, GL2, TTG2 and MYB23) was down-regulated in GhJAZ3 or GhSLR1 transgenic Arabidopsis, while expression of the cell elongation related genes (EXP1, EXP8, EXPL2 and XTH4) was altered in the GhJAZ3 and GhSLR1 transgenic Arabidopsis. Taken together, these results demonstrate that GhJAZ3 and GhSLR1 function in jasmonate and gibberellin mediated epidermal cell differentiation and elongation.
作者机构：
[Xia, Xiao-Cong; Tao, Miao; Li, Xue-Bao; Yan, Jing-Qiu; Ni, Ping; Huang, Geng-Qing; Li, XB; Li, Wen; Han, Li-Hong] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
通讯机构：
[Huang, GQ; Li, XB] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
摘要：
<jats:title>Abstract</jats:title><jats:p>Plant JAZ (Jasmonate ZIM-domain) proteins play versatile roles in multiple aspects of plant development and defense. However, little is known about the JAZ family in allotetraploid upland cotton (<jats:italic>Gossypium hirsutum</jats:italic>) so far. In this study, 30 non-redundant <jats:italic>JAZ</jats:italic> genes were identified in upland cotton through genome-wide screening. Phylogenetic analysis revealed that the 30 proteins in cotton JAZ family are further divided into five groups (I – V), and members in the same group share highly conserved motif structures. Subcellular localization assay demonstrated that GhJAZ proteins are localized in the cell nucleus. Quantitative RT-PCR analysis indicated that <jats:italic>GhJAZs</jats:italic> display different expression patterns in cotton tissues, and most of them could be induced by Jasmonic (JA). Furthermore, some <jats:italic>GhJAZ</jats:italic> genes are preferentially expressed in cotton ovules and fibers, and showed differential expression in ovules of wild type cotton and fiberless mutant (<jats:italic>fl</jats:italic>) during fiber initiation. GhJAZ proteins could interact with each other to form homodimer or heterodimer, and they also interacted with some JA signaling regulators and the proteins involved in cotton fiber initiation. Collectively, our data suggested that some GhJAZ proteins may play important roles in cotton fiber initiation and development by regulating JA signaling as well as some fiber-related proteins.</jats:p>
作者机构：
[Li, Xue-Bao; Huang, Geng-Qing; Tao, Miao; Zhang, Jing-Bo; Hu, Qian-Qian; Li, Deng-Di; Li, Wen; Han, Li-Hong; Wu, Wen-Ying] Cent China Normal Univ, Hubei Key Lab Genet Regulat & Integrat Biol, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Li, XB; Huang, GQ] C;Cent China Normal Univ, Hubei Key Lab Genet Regulat & Integrat Biol, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.
摘要：
TCP proteins are plant-specific transcription factors (TFs), and perform a variety of physiological functions in plant growth and development. In this study, 74 non-redundant TCP genes were identified in upland cotton (Gossypium hirsutum L.) genome. Cotton TCP family can be classified into two classes (class I and class II) that can be further divided into 11 types (groups) based on their motif composition. Quantitative RT-PCR analysis indicated that GhTCPs display different expression patterns in cotton tissues. The majority of these genes are preferentially or specifically expressed in cotton leaves, while some GhTCP genes are highly expressed in initiating fibers and/or elongating fibers of cotton. Yeast two-hybrid results indicated that GhTCPs can interact with each other to form homodimers or heterodimers. In addition, GhTCP14a and GhTCP22 can interact with some transcription factors which are involved in fiber development. These results lay solid foundation for further study on the functions of TCP genes during cotton fiber development.
摘要：
<jats:title>Summary</jats:title><jats:p>Arabinogalactan proteins (<jats:styled-content style="fixed-case">AGP</jats:styled-content>s) are highly glycosylated proteins that play pivotal roles in diverse developmental processes in plants. Type‐<jats:styled-content style="fixed-case">II AG</jats:styled-content> glycans, mostly O‐linked to the hydroxyproline residues of the protein backbone, account for up to 95% w/w of the <jats:styled-content style="fixed-case">AGP</jats:styled-content>, but their functions are still largely unclear. Cotton fibers are extremely elongated single‐cell trichomes on the seed epidermis; however, little is known of the molecular basis governing the regulation of fiber cell development. Here, we characterized the role of a <jats:styled-content style="fixed-case">CAZ</jats:styled-content>y glycosyltransferase 31 (<jats:styled-content style="fixed-case">GT</jats:styled-content>31) family member, GhGalT1, in cotton fiber development. The fiber length of the transgenic cotton overexpressing <jats:italic>GhGalT1</jats:italic> was shorter than that of the wild type, whereas in the <jats:italic>GhGalT1‐</jats:italic>silenced lines there was a notable increase in fiber length compared with wild type. The carbohydrate moieties of <jats:styled-content style="fixed-case">AGP</jats:styled-content>s were altered in fibers of <jats:italic>GhGalT1</jats:italic> transgenic cotton. The galactose: arabinose ratio of <jats:styled-content style="fixed-case">AG</jats:styled-content> glycans was higher in <jats:italic>GhGalT1</jats:italic> overexpression fibers, but was lower in <jats:italic>GhGalT1</jats:italic>‐silenced lines, compared with that in the wild type. Overexpression of <jats:italic>GhGalT1</jats:italic> upregulates transcript levels of a broad range of cell wall‐related genes, especially the fasciclin‐like <jats:styled-content style="fixed-case">AGP</jats:styled-content> (<jats:styled-content style="fixed-case">FLA</jats:styled-content>) backbone genes. An enzyme activity assay demonstrated that GhGalT1 is a β‐1,3‐galactosyltransferase (β‐1,3‐GalT) involved in biosynthesis of the β‐1,3‐galactan backbone of the type‐<jats:styled-content style="fixed-case">II AG</jats:styled-content> glycans of <jats:styled-content style="fixed-case">AGP</jats:styled-content>s. We also show that GhGalT1 can form homo‐ and heterodimers with other cotton <jats:styled-content style="fixed-case">GT</jats:styled-content>31 family members to facilitate <jats:styled-content style="fixed-case">AG</jats:styled-content> glycan assembly of <jats:styled-content style="fixed-case">AGP</jats:styled-content>s. Thus, our data demonstrate that GhGalT1 influences cotton fiber development via controlling the glycosylation of <jats:styled-content style="fixed-case">AGP</jats:styled-content>s, especially <jats:styled-content style="fixed-case">FLA</jats:styled-content>s.</jats:p>
摘要：
Seed oil content is an important agronomic trait in oilseed rape. However, the molecular mechanism of oil accumulation in rapeseeds is unclear so far. In this report, RNA sequencing technique (RNA-Seq) was performed to explore differentially expressed genes in siliques of two Brassica napus lines (HFA and LFA which contain high and low oil contents in seeds, respectively) at 15 and 25 days after pollination (DAP). The RNA-Seq results showed that 65746 and 66033 genes were detected in siliques of low oil content line at 15 and 25 DAP, and 65236 and 65211 genes were detected in siliques of high oil content line at 15 and 25 DAP, respectively. By comparative analysis, the differentially expressed genes (DEGs) were identified in siliques of these lines. The DEGs were involved in multiple pathways, including metabolic pathways, biosynthesis of secondary metabolic, photosynthesis, pyruvate metabolism, fatty metabolism, glycophospholipid metabolism, and DNA binding. Also, DEGs were related to photosynthesis, starch and sugar metabolism, pyruvate metabolism, and lipid metabolism at different developmental stage, resulting in the differential oil accumulation in seeds. Furthermore, RNA-Seq and qRT-PCR data revealed that some transcription factors positively regulate seed oil content. Thus, our data provide the valuable information for further exploring the molecular mechanism of lipid biosynthesis and oil accumulation in B. nupus.
