NMT历史上的今天丨下调膜联蛋白基因GhAnn2抑制棉纤维伸长并减少细胞尖端的Ca2+流入
NMT作为生命科学底层核心技术，是建立活体创新科研平台的必备技术。2005年~2020年，NMT已扎根中国15年。2020年，中国NMT销往瑞士苏黎世大学，正式打开欧洲市场
NMT历史上的今天
2014年05月26日，华中农业大学涂礼莉用NMT发表了标题为Down-regulating annexin gene GhAnn2 inhibits cotton fiber elongation and decreases Ca2+ influx at the cell apex的研究成果。
- 期刊：Plant Molecular Biology
- 主题：下调膜联蛋白基因GhAnn2抑制棉纤维伸长并减少细胞尖端的Ca2+流入
- 标题：Down‑regulating annexin gene GhAnn2 inhibits cotton fiber elongation and decreases Ca2+ influx at the cell apex
- 检测指标：Ca2+流速
- 通讯作者：华中农业大学涂礼莉、唐文鑫
英文摘要
Cotton fiber is a single cell that differentiates from the ovule epidermis and undergoes synchronous elongation with high secretion and growth rate. Apart from economic importance, cotton fiber provides an excellentMsingle-celled model for studying mechanisms of cellgrowth.
Annexins are Ca2+ and phospholipid-binding proteins that have been reported to be localized in multiple cellular compartments and involved in control of vesicle secretions. Although several annexins have been found to be highly expressed in cotton fibers, their functional roles in fiber development remain unknown.
Here, 14 annexin family members were identified from the fully sequenced diploid G. raimondii (D5 genome), half of which were expressed in fibers of the cultivated tetraploid species G. hirsutum (cv. YZ1). Among them, GhAnn2 from the D genome of the tetraploid species displayed high expression level in elongating fiber. The expression of GhAnn2 could be induced by some phytohormones that play important roles in fiber elongation, such as IAA and GA3. RNAimediated down-regulation of GhAnn2 inhibited fiber elongation and secondary cell wall synthesis, resulting in shorter and thinner mature fibers in the transgenic plants.
Measurement with Non-invasive Micro-test Technology revealed that the rate of Ca2+ influx from extracellular to intracellular was decreased at the fiber cell apex of GhAnn2 silencing lines, in comparison to that in the wild type. These results indicate that GhAnn2 may regulate fiber development through modulating Ca2+ fluxes and signaling.
中文摘要（谷歌机翻）
棉纤维是与胚珠表皮不同的单个细胞，并以高分泌和高生长速率经历同步伸长。除了经济上的重要性外，棉纤维还为研究细胞生长机理提供了出色的单细胞模型。
膜联蛋白是Ca2+和磷脂结合蛋白，据报道它们位于多个细胞区室并参与囊泡分泌的控制。尽管已经发现几种膜联蛋白在棉纤维中高度表达，但是它们在纤维发育中的功能作用仍然未知。
在这里，从完全测序的二倍体雷蒙德氏酵母（D5基因组）中鉴定出14个膜联蛋白家族成员，其中一半在培养的四倍体物种hirsutum（cv。YZ1）的纤维中表达。其中，来自四倍体物种的D基因组的GhAnn2在伸长纤维中显示高表达水平。GhAnn2的表达可以被一些在纤维伸长中起重要作用的植物激素诱导，例如IAA和GA3。RNAi介导的GhAnn2的下调抑制了纤维的伸长和次级细胞壁的合成，从而导致转基因植物中成熟纤维的长度越来越短。
通过非损伤微测技术进行的测量显示，与野生型相比，GhAnn2沉默系的纤维细胞顶点从细胞外到细胞内的Ca2+流入速率降低。这些结果表明，GhAnn2可能通过调节Ca2+通量和信号传导来调节纤维发育。
Fig. 4 RNAi silencing of GhAnn2 decreases the rate of Ca2+ influx at the fiber cell apex. a Tip Ca2+ flux of 5 DPA fiber cells was measured by noninvasive scanning ion-selective electrode. Four bolls in one line were analyzed, and at least three fiber cells in one boll were tested. b Average rate of Ca2+ flux of 5 DPA fiber cells. Error bars indicate the SD of three biological replicates.
文章链接：http://ldx.doi.org/10.1007/s11103-014-0208-7
2019版《NMT论文集》已出版
关键词：非损伤微测技术、NMT历史上的今天，Ca2+流速
