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NMT歷*的今天丨Gh7CaM調節活性氧促進棉纖維伸長
NMT是基因功能的活體檢測技術，已被103位諾貝爾獎得主所在單位，及北大、清華、中科院使用。
NMT歷*的今天
2013年12月09日，華中農業大學張獻龍、涂禮莉、唐文鑫用NMT在New Phytologist上發表了標題為The calcium sensor GhCaM7 promotes cotton fiber elongation by modulating reactive oxygen species (ROS) production的研究成果。
期刊：New Phytologist
主題：GhCaM7調節活性氧（ROS）促進棉纖維伸長
標題：The calcium sensor GhCaM7 promotes cotton fiber elongation by modulating reactive oxygen species (ROS) production
影響因子：6.736
檢測指標：Ca2+流速
作者：華中農業大學張獻龍、涂禮莉、唐文鑫
英文摘要
Fiber elongation is the key determinant of ?ber quality and output in cotton (Gossypium hirsutum). Although expression pro?ling and functional genomics provide some data, the mechanism of ?ber development is still not well understood.
Here, a gene encoding a calcium sensor, GhCaM7, was isolated based on its high expres-sion level relative to other GhCaMs in ?ber cells at the fast elongation stage. The level of expression of GhCaM7 in the wild-type and the fuzzless/lintless mutant correspond to the presence and absence, respectively, of ?ber initials.
Overexpressing GhCaM7 promotes early ?ber elongation, whereas GhCaM7 suppression by RNAi delays ?ber initiation and inhibits ?ber elongation. Reactive oxygen species (ROS) play important roles in early ?ber development. ROS induced by exogenous hydrogen perox-ide (H2O2) and Ca2+ starvation promotes early ?ber elongation. GhCaM7 overexpression ?ber cells show increased ROS concentrations compared with the wild-type, while GhCaM7 RNAi ?ber cells have reduced concentrations. Furthermore, we show that H2O2 enhances Ca2+ in?ux into the ?ber and feedback-regulates the expression of GhCaM7.
We conclude that GhCaM7, Ca2+ and ROS are three important regulators involved in early ?ber elongation. GhCaM7 might modulate ROS production and act as a molecular link between Ca2+ and ROS signal pathways in early ?ber development.
中文摘要（谷歌機翻）
纖維伸長率是決定棉花（陸地棉）纖維質量和產量的關鍵因素。盡管表達譜和功能基因組學提供了一些數據，但是纖維發育的機制仍未得到很好的理解。
在此，基于鈣離子傳感器GhCaM7的表達水平相對于其在纖維細胞中處于快速延伸階段的其他GhCaMs高表達水平而被分離出來。GhCaM7在野生型和無絨毛/無絨毛突變體中的表達水平分別對應于纖維首字母的存在與否。
過表達的GhCaM7促進了早期纖維的伸長，而RNAi對GhCaM7的抑制則延遲了纖維的啟動并抑制了纖維的伸長。活性氧（ROS）在纖維早期發育中起重要作用。外源過氧化氫（H2O2）和Ca2+饑餓誘導的ROS促進了早期纖維的伸長。與野生型相比，GhCaM7過表達纖維細胞的ROS濃度升高，而GhCaM7 RNAi纖維細胞的ROS濃度降低。此外，我們表明，H2O2增強了Ca2+的入流，并反饋調節GhCaM7的表達。
我們得出結論，GhCaM7，Ca2+和ROS是參與早期纖維伸長的三個重要調控因子。GhCaM7可能調節ROS的產生，并在早期纖維發育中充當Ca2+和ROS信號通路之間的分子鏈接。?
(b) Ca2+ ?ux during ?ber development was measured by a noninvasive scanning ion-selective electrode technique. During ?ber elongation, there was an increasing Ca2+in?ux from the extracellular to the intracellular environment and the ?ux rate peaked during plasmodesmatal closure from 10 to 15 d postanthesis (DPA). The rate of Ca2+in?ux subsequently decreased during the secondary cell wall synthesis. The inset (lower left) is a schematic diagram for the measurement of Ca2+ ?ux in testing buffer by noninvasive scanning ion-selective electrode. Error bars, SD of nine samples.