摘要：
MADS-box gene family encodes a large number and variety of transcription regulators in plants. In this study, a cDNA, GhMADS9, encoding a typical MADS protein with 230 amino acids was isolated from cotton flower cDNA library. Subsequently, a 1,623 bp genomic DNA fragment of GhMADS9 gene was isolated in cotton by PCR. Compared with its cDNA sequence, six introns were found in GhMADS9 gene. Fluorescent microscopy indicated that GhMADS9 protein localized in the nucleus. Transactivation activity assay in yeast cells revealed that GhMADS9 protein did not show transcriptional activation. Quantitative RT-PCR analysis showed that GhMADS9 was specially expressed in cotton anthers. Further in situ hybridization analysis demonstrated that strong expression of GhMADS9 gene was detected in developing pollens, but no or weak signals were found in the other anther tissues. Furthermore, GhMADS9 expression was dramatically up-regulated in anthers with abscisic acid (ABA) treatment, whereas its activity was down-regulated when treated by gibberellin (GA3). Collectively, our results suggest that GhMADS9 is a transcription factor and might be involved in cotton anther/pollen development and in response to ABA and GA3 signaling.
摘要：
Homeodomain-leucine zipper (HD-Zip) proteins are transcription factors unique to plants. In this study, three cDNAs (designated as GhHB2, GhHB3 and GhHB4) encoding HD-Zip proteins were isolated from cotton cDNA library. GhHB2 gene encodes a protein of 300 amino acids, GhHB3 gene encodes a peptide with 254 amino acids, and GhHB4 gene encodes a protein of 281 amino acids. The deduced proteins, which contain the homeodomain and leucine-rich zipper motif, share relatively high similarities with the other plant HD-Zip proteins. Quantitative RT-PCR analysis indicated that GhHB3 and GhHB4 were preferentially expressed in hypocotyls and cotyledons, whereas GhHB2 gene was predominantly expressed in young stems, at relatively high levels in hypocotyls. Expressions of all the three genes were up-regulated in roots, hypocotyls and cotyledons after GA(3) treatments. Additionally, GhHB4 expression was enhanced by 6-BA treatment. A GhHB2 promoter fragment was isolated from cotton by Genome-Walking PCR. Expression of GUS gene controlled under GhHB2 promoter was examined in the transgenic Arabidopsis plants. Strong GUS staining was detected in cotyledon, veins of the emerging leaves and shoot apices of 5- to 15-day-old transgenic seedlings, but GUS activity became more and more weak as the seedlings further developed. In addition, the promoter activity was induced by exogenous GA, indicating that GhHB2 promoter is very active during early seedling development, and may be GA-inducible. The results suggested that the three HB genes may function in early seedling development of cotton and in response to gibberellin signaling.
作者机构：
[Zhong, Hui; Chen, Liang; Jiang, Weimin; Li, Xuebao; Ren, Feng] Huazhong Normal Univ, Hubei Key Lab Genet Regulat & Integrat Biol, Coll Life Sci, Wuhan 430079, Peoples R China.
通讯机构：
[Li, Xuebao] H;Huazhong Normal Univ, Hubei Key Lab Genet Regulat & Integrat Biol, Coll Life Sci, Wuhan 430079, Peoples R China.
关键词：
Brassica napus;macroarray;gene expression;high-salinity and drought stress
摘要：
High salinity and drought are the major abiotic stresses that adversely affect plant growth and agricultural productivity. To investigate genes that are involved in response to abiotic stresses in Brassica napus, a comprehensive survey of genes induced by high-salinity and drought stresses was done by macroarray analysis. In total, 536 clones were identified to be putative high-salinity- or drought-responsive genes. Among them, 172 and 288 clones are detected to be putative high-salinity- and drought-inducible genes, whereas 141 and 189 are candidates for high-salinity- and drought-suppressed genes, respectively. The functional classification of these genes are indicated that belonged to gene families encoding metabolic enzymes, regulatory factors, components of signal transduction, hormone responses, some abiotic stresses-related proteins, and other processes related to growth and development of B. napus. From the up-regulated candidate genes, some interested genes were further demonstrated to be high-salinity- or/and drought-induced expression by real-time quantitative RT-PCR analysis. The experimental results also revealed that some genes may function in abscisic acid-dependent signaling pathway related to drought or salinity stress. Collectively, the data presented in this study will facilitate the understanding of molecular mechanism of B. napus in response to high-salinity and drought stresses, and also provide us the basis of effective genetic engineering strategies for improving stress tolerance of B. napus.
摘要：
Proteins of the 14-3-3 family regulate a divergent set of signalling pathways in all eukaryotic organisms. In this study, several cDNAs encoding 14-3-3 proteins were isolated from a cotton fibre cDNA library. The Gh14-3-3 genes share high sequence homology at the nucleotide level in the coding region and at the amino acid level. Real-time quantitative RT-PCR analysis indicated that the expression of these Gh14-3-3 genes is developmentally regulated in fibres, and reached their peak at the stage of rapid cell elongation of fibre development. Furthermore, overexpression of Gh14-3-3a, Gh14-3-3e, and Gh14-3-3L in fission yeast promoted atypical longitudinal growth of the host cells. Yeast two-hybrid analysis revealed that the interaction between cotton 14-3-3 proteins is isoform selective. Through yeast two-hybrid screening, 38 novel interaction partners of the six 14-3-3 proteins (Gh14-3-3a, Gh14-3-3e, Gh14-3-3f, Gh14-3-3g, Gh14-3-3h, and Gh14-3-3L), which are involved in plant development, metabolism, signalling transduction, and other cellular processes, were identified in cotton fibres. Taking these data together, it is proposed that the Gh14-3-3 proteins may participate in regulation of fibre cell elongation. Thus, the results of this study provide novel insights into the 14-3-3 signalling related to fibre development of cotton.
通讯机构：
[Li, Xue-Bao] H;Huazhong Normal Univ, Coll Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
关键词：
ADF;cotton;F-actin;gene expression;pollen development
摘要：
To investigate whether the high expression levels of actin-depolymerizing factor genes are related to pollen development, three GhADF genes (cDNAs) were isolated and characterized in cotton. Among them, GhADF6 and GhADF8 were preferentially expressed in petals, whereas GhADF7 displayed the highest level of expression in anthers, revealing its anther specificity. The GhADF7 transcripts in anthers reached its peak value at flowering, suggesting that its expression is developmentally-regulated in anthers. The GhADF7 gene including the promoter region was isolated from the cotton genome. To demonstrate the specificity of the GhADF7 promoter, the 5′-flanking region, including the promoter and 5′-untranslated region, was fused with the GUS gene. Histochemical assays demonstrated that the GhADF7:GUS gene was specifically expressed in pollen grains. When pollen grains germinated, very strong GUS staining was detected in the elongating pollen tube. Furthermore, overexpression of GhADF7 gene in Arabidopsis thaliana reduced the viable pollen grains and, consequently, transgenic plants were partially male-sterile. Overexpression of GhADF7 in fission yeast (Schizosaccharomyces pombe) altered the balance of actin depolymerization and polymerization, leading to the defective cytokinesis and multinucleate formation in the cells. Given all the above results together, it is proposed that the GhADF7 gene may play an important role in pollen development and germination.
作者机构：
[Wang, Xiu-Lan; Li, Xue-Bao] Huazhong Normal Univ, Coll Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
通讯机构：
[Wang, Xiu-Lan] H;Huazhong Normal Univ, Coll Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
关键词：
cotton (Gossypium hirsutum);acyl‐CoA synthetase;microsporogenesis;GhACS1 gene;suppression of gene expression
摘要：
Microsporogenesis, associated with the functional expression of many genes, is a highly programmed and regulated process in flowering plants. To elucidate the roles of genes during anther development, two anther-specific cDNAs (designated GhACS1 and GhACS2) encoding acyl-CoA synthetases (ACSs) were isolated from a cotton (Gossypium hirsutum) flower cDNA library. Subsequently, the corresponding GhACS1 gene was isolated from a cotton genomic DNA library. Real-time quantitative RT-PCR and northern blot analyses revealed that GhACS1 transcripts were predominantly accumulated in the developing anthers of cotton. The specificity of GhACS1 expression in primary sporogenous cells (PSCs), pollen mother cells (PMCs), microspores, and tapetal cells was demonstrated by in situ hybridization as well as histochemical assay of GUS expression controlled under the GhACS1 promoter. High levels of GhACS1 activity are crucial for fatty acid metabolism in PSCs, PMCs, microspores and particularly tapetal cells. Reduction of ACS enzymatic activity by suppressing GhACS1 expression severely affected the tapetal cells and consequently blocked normal microsporogenesis in early anther development. Aberrant and defective microspores were generated in the transgenic anthers. As a result, the transgenic plants failed to produce functional pollen grains and were male-sterile, suggesting that the GhACS1 gene is required for normal microsporogenesis in early anther development of cotton.
作者机构：
[W. -B. Cao; L. -L. Zheng; Z. -F. Zhang; X. -B. Li] Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, HuaZhong Normal University, Wuhan, China
通讯机构：
[X. -B. Li] H;Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, HuaZhong Normal University, Wuhan, China
摘要：
Analysis of genetic diversity in maize populations is a very important step for understanding genetic structure and subsequently for genetic manipulations in maize breeding. Sh2, Bt2, Sh1, Wx1, Ae1 and Su1 involved in starch biosynthesis are important genes associated with yield and quality traits in maize breeding programs. In this study, genetic diversity of these six genes in 67 Chinese elite maize inbred lines was measured using single-nucleotide amplified polymorphisms (SNAPs). The results indicated that the number of haplotypes of each gene and population was far less than theoretically expected 2
n
(n = the number of the SNAPs). Phenetic clustering analysis showed that the kernel phonetic (semi-) dent and (semi-) flint lines were belong to distinct subclusters based on haplotypes of SNAPs, with a few exceptions. In addition, the genetic origin of these maize inbred lines was associated with the clustered subgroups. Intragenic linkage disequilibrium (LD) was observed in some of the SNAPs in Bt2, Sh1 and Ae1, while intergenic LD was observed in some of the SNAPs in Bt2, Sh1 and Su1. Association study of kernel phenotypes and SNAP haplotypes showed that the (semi-) dent and (semi-) flint lines had the common haplotype of TA and CC at two SNAP sites in Bt2 (Bt2-2 and Bt2-5), respectively. Two haplotypes of ATGT and GTGC at four SNAP sites in Sh1 (Sh1-2, Sh1-3, Sh1-4 and Sh1-5) were associated with temperature and tropical origin of the maize inbred lines, respectively.
摘要：
Arabinogalactan proteins (AGPs) are a large family of highly glycosylated of hydroxyproline-rich glycoproteins that play important roles in plant growth, development, and signal transduction. A cDNA encoding a putative classical AGP named GhH6L was isolated from cotton fiber cDNA libraries, and the deduced protein contains 17 copies of repetitive motif of X-Y-proline-proline-proline (where X is serine or alanine and Y is threonine or serine). Northern blotting analysis and quantitative RT-PCR results showed that it was preferentially expressed in 10 days post-anthesis (dpa) fibers and was also developmentally regulated. A promoter fragment was isolated from cotton (Gossypium hirsutum) by genome walking PCR. Expression of beta-glucuronidase (GUS) gene under the GhH6L promoter was examined in the transgenic Arabidopsis plants; only petiole and pedicel were stained, no staining was detected in other tissues. Subcellular localization indicated that GhH6L was localized to the plasma membrane and in the cytoplasm. These data further our understanding of GhH6L as well as shed light on functional insight to GhH6L in cotton.
摘要：
To enhance the survival probability in cold stress, plant cells often increase their cold- and freezing-tolerance in response to low, nonfreezing temperatures by expressing some cold-related genes. In present study, a cotton gene encoding tonoplast intrinsic protein (TIP) was isolated from a cotton seedling cDNA library, and designated as GhTIP1;1. GFP fluorescent microscopy indicated that GhTIP1;1 protein was localized to the vacuolar membrane. Assay on GhTIP1;1 expression in Xenopus laevis oocytes demonstrated that GhTIP1;1 protein displayed water channel activity and facilitated water transport to the cells. At normal conditions, GhTIP1;1 transcripts were predominantly accumulated in roots and hypocotyls, but less abundance in other tissues of cotton. The GhTIP1;1 expression was dramatically up-regulated in cotyledons, but down-regulated in roots within a few hours after cotton seedlings were cold-treated. Overexpression of GhTIP1;1 in yeast (Schizosaccharomyces pombe) significantly enhanced the cell survival probability, suggesting that the GhTIP1;1 protein is involved in cell freezing-tolerance.
摘要：
14-3-3 proteins are phosphoserine-binding proteins that regulate the activities of a wide array of targets via direct protein-protein interactions, and may play an important role in response to biotic and abiotic stresses. In this study, two cDNAs ( designated as Gh14-3-3b and Gh14-3-3c) encoding putative 14-3-3 proteins were isolated from cotton cDNA libraries. Gh14-3-3b gene encodes a protein of 268 amino acids, while Gh14-3-3c gene encodes a protein of 261 amino acids. Real-time RT-PCR analysis revealed that both the Gh14-3-3b and Gh14-3-3c genes were preferentially expressed in roots. The transcript levels of both the genes were the highest in 3-day-old roots, and then dramatically decreased to relatively low levels in parallel with root development. In addition, the expression of these Gh14-3-3 genes in roots was significantly up regulated by salt treatments, suggesting that they may be involved in the signaling pathways in response to salt stress in cotton. (C) 2008 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.
