Effects of High Temperature Stress o

Effects of High Temperature Stress on Microscopic and Ultrastructural Characteristics of Mesophyll Cells in Flag Leaves

The microscopic and ultrastructural characteristics of mesophyll cells in flag leaves of two rice lines (a thermo- sensitive line 4628 and a thermo-resistant line 996) under high temperature stress (37°C during 8:00-17:00 and 30°C during 17:00-8:00) were investigated using an optical and a transmission electron microscopy. The membrane permeability and malondialdehyde content increased under the high temperature stress, and the increase of both variables was greater in the line 4628 than in the line 996. Under the high temperature stress, the line 996 showed tightly arranged mesophyll cells in flag leaves, fully developed vascular bundles and some closed stomata, whereas the line 4628 suffered from injury because of undeveloped vascular bundles, loosely arranged mesophyll cells and opened stomata. The mesophyll cells in flag leaves of the line 4628 were severely damaged under the high temperature stress, i.e. the chloroplast envelope became blurred, the grana thylakoid layer was arranged loosely and irregularly, the stroma layer disappeared, many osmiophilic granules appeared within the chloroplast, the outer membrane of mitochondria and the nucleus disintegrated and became blurred, the nucleolus disappeared, and much fibrillar-granular materials appeared within the nucleus. In contrast, the mesophyll cells in flag leaves of the line 996 maintained an intact ultrastructure under the high temperature stress. From these results, it is suggested that the ultrastructural modification of the cell membrane system is the primary plant response to high temperature stress and can be used as an index to evaluate the crop heat tolerance.

作 者： ZHANG Gui-lian CHEN Li-yun ZHANG Shun-tang ZHENG Hua LIU Guo-hua   作者单位： Rice Research Institute, Hunan Agricultural University, Changsha 410128, China  刊 名： 水稻科学（英文版）  英文刊名： RICE SCIENCE  年，卷(期)： 2009 16(1)  分类号： S5  关键词： rice   high temperature stress   heat tolerance   flag leaf   microscopic characteristic   ultrastructure characteristic   mesophyll cell   cytology  

【Effects of High Temperature Stress o】相关文章：

Cause and Effects of Iron Deficiencies05-04

It is (high) time that05-04

Life of High Quality05-04

单词high的中文是什么意思02-12

O的联想作文08-09

a o e 教案04-25

学科术语 O05-04

（精华）o的联想作文10-16

a o e拼音教案02-25

o型腿绑腿的方法08-23