Plastid movement impaired 2, a new gene involved in normal blue-light-induced chloroplast movements in Arabidopsis
Plastid movement impaired 2, a new gene involved in normal blue-light-induced chloroplast movements in Arabidopsis
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DOI：
10.1104/pp.106.080333
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发表时间：
2006-08-01
期刊：
影响因子：
7.4
通讯作者：
Hangarter, Roger P.
中科院分区：
文献类型：
--
作者：
Luesse, Darron R.;DeBlasio, Stacy L.;Hangarter, Roger P.
叶绿体以光依赖的方式运动，可以调节植物细胞的光合作用潜力。光诱导叶绿体运动所需基因的鉴定开始定义控制这些运动的分子机制。在这项工作中，我们描述了质体运动受损2（pmi 2），在拟南芥（拟南芥）的突变体，显示衰减的叶绿体运动在中等和高的光强度下，同时保持正常的运动响应在低光强度下。在野生型植物中，蓝光的能量密度率低于20 μ mol m（-2）s（-1）时，叶绿体会聚集在平周细胞壁上，而光强超过20 μ mol m（-2）s（-1）时，叶绿体会向垂周细胞壁移动（回避反应）。然而，在低于75 μ mol m（-2）s（-1）的光强度下，pmi 2叶片中的叶绿体移动到平周壁; pmi 2中的叶绿体移动到垂周细胞壁需要100 mmol m（-2）s（-1）的蓝光，这表明突变体中回避反应的光阈值发生了变化。pmi 2突变已被映射到一个基因，该基因编码一种功能未知的蛋白质，在N端有一个大的卷曲螺旋结构域和一个假定的P环。PMI 2与PMI 15具有序列和结构相似性，PMI 15是拟南芥中的另一种未知蛋白，当突变时，会导致叶绿体在强光下回避的缺陷。
Chloroplasts move in a light-dependent manner that can modulate the photosynthetic potential of plant cells. Identification of genes required for light-induced chloroplast movement is beginning to define the molecular machinery that controls these movements. In this work, we describe plastid movement impaired 2 (pmi2), a mutant in Arabidopsis ( Arabidopsis thaliana) that displays attenuated chloroplast movements under intermediate and high light intensities while maintaining a normal movement response under low light intensities. In wild-type plants, fluence rates below 20 mu mol m(-2) s(-1) of blue light lead to chloroplast accumulation on the periclinal cell walls, whereas light intensities over 20 mu mol m(-2) s(-1) caused chloroplasts to move toward the anticlinal cell walls ( avoidance response). However, at light intensities below 75 mu mol m(-2) s(-1), chloroplasts in pmi2 leaves move to the periclinal walls; 100 mmol m(-2) s(-1) of blue light is required for chloroplasts in pmi2 to move to the anticlinal cell walls, indicating a shift in the light threshold for the avoidance response in the mutant. The pmi2 mutation has been mapped to a gene that encodes a protein of unknown function with a large coiled-coil domain in the N terminus and a putative P loop. PMI2 shares sequence and structural similarity with PMI15, another unknown protein in Arabidopsis that, when mutated, causes a defect in chloroplast avoidance under high-light intensities.