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
标题：Down‑regulating annexin gene GhAnn2 inhibits cotton fiber elongationand decreases Ca2+ influx at the cell apex
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.
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.