The accumulation of reactive oxygen species （ROS） is involved in plant cell development. In plant, class III peroxidases are heme-containing enzymes encoded by a large multi-gene family participated in the release o...The accumulation of reactive oxygen species （ROS） is involved in plant cell development. In plant, class III peroxidases are heme-containing enzymes encoded by a large multi-gene family participated in the release or consumption of ROS. The specific function of each member of the family is still elusive. Here, we showed that ROS was significantly generated during cotton fiber initiation and elongation, whereas, application of NADPH oxidase inhibitor diphenyleneiodonium （DPI） and peroxidase inhibitor salicylhydroxamic acid （SHAM） to the wild-type cotton ovule culture significantly suppressed fiber growth, respectively. Their inhibitory effects were caused by the reduction of superoxide radical （O2^-）. Ten GhPOX genes （cDNAs） encoding cotton class III peroxidases were isolated, among them eight GhPOX genes were reported for the first time. Microarray analyses indicated that GhPOX1 was the mostly predominantly expressed in fast-elongating cotton fiber cells. Real-time quantitative PCR analysis revealed the transcript level of GhPOX1 was over 400-fold higher in growing fiber cells than in ovules, flowers, roots, stems and leaves. To reveal the role of GhPOX1 in plant development, its Arabidopsis orthologue atpox13 mutant was demonstrated to be defective in branch root development. Taken together, the data suggest that GhPOX1 plays an important role during fiber cell elongation possibly by mediating production of reactive oxygen species.展开更多
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 ...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.展开更多
Fiber length of cotton(Gossypium hirsutum L.)decreases under drought stress,potassium(K)could diminish the decreased caused by drought,but the mechanism associated with this alleviation effect is not clear.We evaluate...Fiber length of cotton(Gossypium hirsutum L.)decreases under drought stress,potassium(K)could diminish the decreased caused by drought,but the mechanism associated with this alleviation effect is not clear.We evaluated the effect of K on fiber elongation using two cotton cultivars,Simian 3 and Siza 3,grown in well-watered and drought-stressed conditions.Potassium fertilizer(K2O)was applied 0,150,or 300 kg ha?1 in each growing condition.Drought stress reduced the final fiber length due to a decline in the maximum rate of rapid elongation(Vmax,mmday?1).The application of K alleviated the droughtinduced fiber length reduction by increasing Vmax.At 10 and 15 days post-anthesis(DPA),drought significantly reduced osmotic potential(OP)and increased K+and malate contents at all K rates,relative to well-watered conditions,which was associated with increased activities of phosphoenolpyruvate carboxylase(PEPC),V-ATPase,PPase,and PM H+-ATPase in cotton fiber.However,the relative contribution of K+and malate to OP declined under drought in comparison with well-watered condition.Compared with control without K,K application decreased OP and increased the accumulation of osmolytes(K+,malate and soluble sugar)as well as the activities of related enzymes in fiber irrespective of water treatments.Moreover,K application increased osmotic adjustment during drought,and improved the contribution of K+and malate to OP,especially under drought stress.This study showed that drought decreased fiber length by reducing Vmax,and K application ameliorates the decline in fiber elongation due to drought by enhancing osmolytes accumulation and their contribution to OP in fiber cells.展开更多
基金supported by grants from the National Basic Research Program of China (No. 2004CB117302)the National High-tech Research Program of China (No. 2006AA10A109-1 and 2007AA10Z136).
文摘The accumulation of reactive oxygen species （ROS） is involved in plant cell development. In plant, class III peroxidases are heme-containing enzymes encoded by a large multi-gene family participated in the release or consumption of ROS. The specific function of each member of the family is still elusive. Here, we showed that ROS was significantly generated during cotton fiber initiation and elongation, whereas, application of NADPH oxidase inhibitor diphenyleneiodonium （DPI） and peroxidase inhibitor salicylhydroxamic acid （SHAM） to the wild-type cotton ovule culture significantly suppressed fiber growth, respectively. Their inhibitory effects were caused by the reduction of superoxide radical （O2^-）. Ten GhPOX genes （cDNAs） encoding cotton class III peroxidases were isolated, among them eight GhPOX genes were reported for the first time. Microarray analyses indicated that GhPOX1 was the mostly predominantly expressed in fast-elongating cotton fiber cells. Real-time quantitative PCR analysis revealed the transcript level of GhPOX1 was over 400-fold higher in growing fiber cells than in ovules, flowers, roots, stems and leaves. To reveal the role of GhPOX1 in plant development, its Arabidopsis orthologue atpox13 mutant was demonstrated to be defective in branch root development. Taken together, the data suggest that GhPOX1 plays an important role during fiber cell elongation possibly by mediating production of reactive oxygen species.
基金supported by the National Natural Sciences Foundation of China (No. 30871317)the project from Ministry of Agriculture of China for transgenic research (No. 2009ZX08009-117B)
文摘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.
基金financial support from the National Key Research and Development Program of China (2018YFD1000900)Jiangsu Collaborative Innovation Center for Modern Crop Production (JCIC-MCP)Jiangsu Overseas Research and Training Program for University Prominent Young and Middle-aged Teachers and President (2016), China
文摘Fiber length of cotton(Gossypium hirsutum L.)decreases under drought stress,potassium(K)could diminish the decreased caused by drought,but the mechanism associated with this alleviation effect is not clear.We evaluated the effect of K on fiber elongation using two cotton cultivars,Simian 3 and Siza 3,grown in well-watered and drought-stressed conditions.Potassium fertilizer(K2O)was applied 0,150,or 300 kg ha?1 in each growing condition.Drought stress reduced the final fiber length due to a decline in the maximum rate of rapid elongation(Vmax,mmday?1).The application of K alleviated the droughtinduced fiber length reduction by increasing Vmax.At 10 and 15 days post-anthesis(DPA),drought significantly reduced osmotic potential(OP)and increased K+and malate contents at all K rates,relative to well-watered conditions,which was associated with increased activities of phosphoenolpyruvate carboxylase(PEPC),V-ATPase,PPase,and PM H+-ATPase in cotton fiber.However,the relative contribution of K+and malate to OP declined under drought in comparison with well-watered condition.Compared with control without K,K application decreased OP and increased the accumulation of osmolytes(K+,malate and soluble sugar)as well as the activities of related enzymes in fiber irrespective of water treatments.Moreover,K application increased osmotic adjustment during drought,and improved the contribution of K+and malate to OP,especially under drought stress.This study showed that drought decreased fiber length by reducing Vmax,and K application ameliorates the decline in fiber elongation due to drought by enhancing osmolytes accumulation and their contribution to OP in fiber cells.
