Secretory low molecular weight phospholipase A2 plays important roles in cell elongation and shoot gravitropism in Arabidopsis
Secretory low molecular weight phospholipase A2 plays important roles in cell elongation and shoot gravitropism in Arabidopsis
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DOI：
10.1105/tpc.014423
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发表时间：
2003-09-01
期刊：
影响因子：
11.6
通讯作者：
Ryu, SB
中科院分区：
文献类型：
--
作者：
Lee, HY;Bahn, SC;Ryu, SB
为了阐明磷脂酶A（2）在植物中的细胞功能，分离了一个拟南芥cDNA，编码分泌型低分子量磷脂酶A（2）（AtsPLA（2）beta）。转基因植物的表型分析表明，AtsPLA（2）beta的过表达促进细胞伸长，导致叶柄和花序茎延长，而RNA干扰介导的AtsPLA（2）beta表达沉默延缓细胞伸长，导致叶柄和茎缩短。AtsPLA（2）beta在花序茎和下胚轴的活跃生长组织的皮层、维管和内胚层细胞中表达。AtsPLA（2）β然后被分泌到细胞外空间，在那里细胞壁酸化的信号被认为发生。AtsPLA（2）β过表达或沉默的转基因植物在花序、茎和下胚轴中表现出向重力性的改变。AtsPLA（2）beta的表达被生长素处理和经历向重力反应的花序茎的弯曲区域快速诱导。这些结果表明，AtsPLA（2）beta通过介导生长素诱导的细胞伸长来调节细胞伸长过程，并在芽向重力性中发挥重要作用。
To elucidate the cellular functions of phospholipase A(2) in plants, an Arabidopsis cDNA encoding a secretory low molecular weight phospholipase A(2) (AtsPLA(2)beta) was isolated. Phenotype analyses of transgenic plants showed that overexpression of AtsPLA(2)beta promotes cell elongation, resulting in prolonged leaf petioles and inflorescence stems, whereas RNA interference-mediated silencing of AtsPLA(2)beta expression retards cell elongation, resulting in shortened leaf petioles and stems. AtsPLA(2)beta is expressed in the cortical, vascular, and endodermal cells of the actively growing tissues of inflorescence stems and hypocotyls. AtsPLA(2)beta then is secreted into the extracellular spaces, where signaling for cell wall acidification is thought to occur. AtsPLA(2)beta-overexpressing or -silenced transgenic plants showed altered gravitropism in inflorescence stems and hypocotyls. AtsPLA(2)beta expression is induced rapidly by auxin treatment and in the curving regions of inflorescence stems undergoing the gravitropic response. These results suggest that AtsPLA(2)beta regulates the process of cell elongation and plays important roles in shoot gravitropism by mediating auxin-induced cell elongation.