Arabidopsis thaliana calmodulin-like protein CML24 regulates pollen tube growth by modulating the actin cytoskeleton and controlling the cytosolic Ca2+ concentration
Arabidopsis thaliana calmodulin-like protein CML24 regulates pollen tube growth by modulating the actin cytoskeleton and controlling the cytosolic Ca2+ concentration
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DOI：
10.1007/s11103-014-0220-y
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发表时间：
2014-08
影响因子：
5.1
通讯作者：
Xue Yang;Shuang-Shuang Wang-Shuang;Meirong Wang;Zhu Qiao;Chanchan Bao;Wei Zhang
中科院分区：
文献类型：
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作者：
Xue Yang;Shuang-Shuang Wang-Shuang;Meirong Wang;Zhu Qiao;Chanchan Bao;Wei Zhang
胞质游离钙（[Ca ~（2+）]cyt）是花粉萌发和花粉管生长过程中必不可少的物质，可被类钙调蛋白（CML）所感知。拟南芥基因组编码超过50个CML，其中大部分的生理作用是未知的。在这里，我们表明，基因AtCML 24作为一个调节器的花粉萌发和花粉管延伸，因为功能丧失突变体产生的花粉萌发速度比野生型（WT）植物，花粉管延伸的速度较慢，和最终长度的花粉管较短。theml 24突变体产生的萌发花粉和延伸花粉管胞质中的[Ca ~（2+）]浓度均高于野生型，且花粉管延伸对外界[K ~+]和[Ca ~（2+）]的变化不敏感。cm 124突变体产生的花粉和花粉管的特征是肌动蛋白细胞骨架紊乱，对latrunculin B作用的敏感性降低。这些观察结果支持CML 24和[Ca ~（2+）]cytand的参与肌动蛋白组织之间的相互作用，从而影响花粉萌发和花粉管伸长。
Cytosolic free calcium ([Ca2+]cyt), which is essential during pollen germination and pollen tube growth, can be sensed by calmodulin-like proteins (CMLs). TheArabidopsis thalianagenome encodes over 50 CMLs, the physiological role(s) of most of which are unknown. Here we show that the geneAtCML24acts as a regulator of pollen germination and pollen tube extension, since the pollen produced by loss-of-function mutants germinated less rapidly than that of wild-type (WT) plants, the rate of pollen tube extension was slower, and the final length of the pollen tube was shorter. The [Ca2+]cytwithin germinated pollen and extending pollen tubes produced by thecml24mutant were higher than their equivalents in WT plants, and pollen tube extension was less sensitive to changes in external [K+] and [Ca2+]. The pollen and pollen tubes produced bycml24mutants were characterized by a disorganized actin cytoskeleton and lowered sensitivity to the action of latrunculin B. The observations support an interaction between CML24 and [Ca2+]cytand an involvement of CML24 in actin organization, thereby affecting pollen germination and pollen tube elongation.