Cheng Yuan, Lu Lili, Yang Zhaoen, Wu Zhixia, Qin Wenqiang, Yu Daoqian, Ren Zhongying, Li Yi, Wang Lingling, Li Fuguang, Yang Zuoren
State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; Huazhong Agricultural University, Wuhan 430070, China.
State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China.
Plant Physiol Biochem. 2016 Dec;109:128-136. doi: 10.1016/j.plaphy.2016.09.009. Epub 2016 Sep 15.
Calcium signaling regulates many developmental processes in plants. Calmodulin (CaM) is one of the most conserved calcium sensors and has a flexible conformation in eukaryotes. The molecular functions of CaM are unknown in cotton, which is a major source of natural fiber. In this study, a Gossypium hirsutum L.CaM7-like gene was isolated from upland cotton. Bioinformatics analysis indicated that the GhCaM7-like gene was highly conserved as compared with Arabidopsis AtCaM7. The GhCaM7-like gene showed a high expression level in elongating fibers. Expression of β-glucuronidase was observed in trichomes on the stem, leaf and root in transgenic Arabidopsis plants of a PRO:GUS fusion. Silencing of the GhCaM7-like gene resulted in decreased fiber length, but also caused reduction in stem height, leaf dimensions, seed length and 100-seed weight, in comparison with those of the control. Reduced expression of the GhCaM7-like gene caused decreased Ca influx in cells of the leaf hypodermis and stem apex, and down-regulation of GhIQD1 (IQ67-domain containing protein), GhAnn2 (Annexins) and GhEXP2 (Expansin). These results indicate that the GhCaM7-like gene plays a vital role in calcium signaling pathways, and may regulate cotton fiber elongation and biomass production by affecting Ca signatures and downstream signaling pathways of CaM.
钙信号传导调控植物中的许多发育过程。钙调蛋白（CaM）是最保守的钙传感器之一，在真核生物中具有灵活的构象。在作为天然纤维主要来源的棉花中，CaM的分子功能尚不清楚。在本研究中，从陆地棉中分离出一个陆地棉CaM7-like基因。生物信息学分析表明，与拟南芥AtCaM7相比，GhCaM7-like基因高度保守。GhCaM7-like基因在伸长的纤维中表现出高表达水平。在PRO:GUS融合的转基因拟南芥植株的茎、叶和根的毛状体中观察到β-葡萄糖醛酸酶的表达。与对照相比，GhCaM7-like基因的沉默导致纤维长度缩短，同时还导致茎高、叶尺寸、种子长度和百粒重降低。GhCaM7-like基因表达的降低导致叶下表皮和茎尖细胞中钙内流减少，以及GhIQD1（含IQ67结构域的蛋白）、GhAnn2（膜联蛋白）和GhEXP2（扩展蛋白）的下调。这些结果表明，GhCaM7-like基因在钙信号通路中起关键作用，可能通过影响钙信号特征和CaM的下游信号通路来调控棉花纤维伸长和生物量生产。
