The avoidance and aggregative movements of mesophyll chloroplasts in C4 monocots in response to blue light and abscisic acid
The avoidance and aggregative movements of mesophyll chloroplasts in C4 monocots in response to blue light and abscisic acid
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DOI：
10.1093/jxb/err008
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发表时间：
2011-05-01
影响因子：
6.9
通讯作者：
Taniguchi, Mitsutaka
中科院分区：
文献类型：
--
作者：
Maai, Eri;Shimada, Shouu;Taniguchi, Mitsutaka
在 C-4 植物中，叶肉 (M) 叶绿体沿细胞壁随机分布，而束鞘叶绿体位于向心或离心位置。此前有报道称，只有M叶绿体响应极强的光或环境胁迫而聚集重新分布到束鞘侧。与脱落酸 (ABA) 一起孵育后，M 叶绿体的聚集运动也会以光依赖性方式诱导。本文在 C-4 植物的两种不同亚型（小米和玉米）中研究了活性氧 (ROS) 和红/蓝光在 M 叶绿体聚集运动中的参与情况。外源施加过氧化氢或ROS清除剂不能改变M叶绿体运动对光和ABA的响应模式。蓝光照射本质上诱导了M叶绿体沿着垂周壁的侧面重新排列，平行于入射光的方向，这类似于C-3叶绿体的回避运动。在 ABA 存在的情况下，大多数 M 叶绿体表现出响应蓝光而不是红光的聚集运动。这些结果表明，ROS 不参与聚集运动的信号转导，而 ABA 可以将蓝光诱导的 C-4-M 叶绿体的回避运动转变为聚集运动。
In C-4 plants, mesophyll (M) chloroplasts are randomly distributed along the cell walls, whereas bundle sheath chloroplasts are located in either a centripetal or centrifugal position. It was reported previously that only M chloroplasts aggregatively redistribute to the bundle sheath side in response to extremely strong light or environmental stresses. The aggregative movement of M chloroplasts is also induced in a light-dependent fashion upon incubation with abscisic acid (ABA). The involvement of reactive oxygen species (ROS) and red/blue light in the aggregative movement of M chloroplasts are examined here in two distinct subtypes of C-4 plants, finger millet and maize. Exogenously applied hydrogen peroxide or ROS scavengers could not change the response patterns of M chloroplast movement to light and ABA. Blue light irradiation essentially induced the rearrangement of M chloroplasts along the sides of anticlinal walls, parallel to the direction of the incident light, which is analogous to the avoidance movement of C-3 chloroplasts. In the presence of ABA, most of the M chloroplasts showed the aggregative movement in response to blue light but not red light. Together these results suggest that ROS are not involved in signal transduction for the aggregative movement, and ABA can shift the blue light-induced avoidance movement of C-4-M chloroplasts to the aggregative movement.