棉纤维细胞发育过程中钙离子内流和钙依赖蛋白激酶活性的动态变化  

Ethylene and VLCFA Promote Cotton Fiber Growth by Stimulating Ca^(2+) Ion Influx and Activation of Several Ca^(2+)-Dependent Protein Kinases

作　　者：肖光辉[1] 梅文倩[1] 朱玉贤[1,2] 

机构地区：[1]北京大学生命科学学院,蛋白质与植物基因研究国家重点实验室,北京100871 [2]国家植物基因研究中心(北京),北京100101

出　　处：《中国科学：生命科学》2013年第10期886-896,共11页Scientia Sinica(Vitae)

基　　金：国家重点基础研究发展计划(批准号:2010CB126000);国家自然科学基金(批准号:90717009)资助

摘　　要：随着大规模棉花纤维细胞发育的表达谱分析以及系统性生理和生化研究,维持纤维细胞快速伸长的机制也逐渐被阐明,超长链脂肪酸和植物激素乙烯在该过程中发挥重要作用.本研究检测到在棉花纤维发育初期细胞外钙离子内流增加.棉花cDNA芯片及QRT-PCR的数据均显示,CPK1,CPK32和CRK5的表达在纤维伸长期显著升高.系统研究发现,随着纤维细胞的伸长,CPK总活性显著增加,在开花后10~15天达到最高,提示CPK类激酶在纤维发育过程中扮演重要角色.体外胚珠培养加入CPK的抑制剂TFP或W-7导致纤维不能伸长.在体外胚珠培养中加入外源的乙烯或者超长链脂肪酸可以刺激钙离子的瞬时内流和CPK的活性.因此推断,乙烯或者超长链脂肪酸通过促进CPK的活性增强钙离子内流,从而调控纤维细胞的发育.The regulatory mechanism controlling the sustained cotton fiber cell elongation is gradually being elucidated by coupling genome-wide transcriptome profiling with systematic biochemical and physiological studies. Very long chain fatty acids （VLCFA, C24：0） and the plant hormone ethylene have been reported to be involved in this process. In the current study, we detected a significant Ca2＋ influx from extracellular spaces during the period of fiber cell initiation. This Ca2~ ion burst was observed specifically in wild-type cotton ovules with developing fiber initials and not in ovules of the fuzzless-lintless （fl） mutant that produced no fiber initials. Systematic studies found that total Ca2＋-dependent protein kinase （CPK） activities increased consistently in wild-type ovules soon after fiber development. Only limited increase in CPK activities was shown in ovules of both the wild-type and fl mutant over the same growth period. Fiber growth was blocked completely by adding chemicals such as trifluoperazine （TFP） and N-（6-aminohexyl）-5-chloro-l-naphthalenesulfonamide （W-7） into ovule culture medium, but not by N-（6- aminohexyl）-l-naphthalenesulfonamide （W-5）. Collectively, our data indicate that ethylene and VLCFA regulate fiber cell growth by enhancing Ca2~ ion influx and by promoting CPK activities.

关 键 词：陆地棉 钙离子 钙离子依赖的蛋白激酶 乙烯 超长链脂肪酸 

分 类 号：S562[农业科学—作物学]