水稻温敏型突变体叶片间断失绿的超微结构

Ultrastructural Observation on Chloroplast of the Thermo-sensitive Green-yellow Banded Leaf Mutant in Rice(Oryza ssp. indica )

在短时降温诱导下，水稻温敏型突变体１１０３ｓ（Ｏｒｙｚａ ｓａｔｉｖａ ｓｓｐ．ｉｎｄｉｃａ）植株间断失绿性状表达（临界温度２３．１℃）过程中，叶绿体含量的增减与叶色变化相符。电镜观察发现，性状表达时叶片间断失绿区叶绿体内部结构发生退化，呈现基粒垛叠片层数的异常减少，或基粒消失仅剩基粒残迹，有的甚至整个叶绿体为高电子密度的囊泡状结构。但在同一叶片的绿区，叶绿体仅表现基粒片层数减少、排列不规则，嗜锇小球聚集。在叶片失绿区的复绿过程中，叶绿体的这些变化又可逆转，内部结构重建，最后整个叶绿体结构基本恢复正常。水稻温敏突变体１１０３ｓ叶片间断失绿性状表达过程，实质上是一个由温度调控的叶绿体结构退化与修复的可逆过程。

The green-yellow bands interrupted discolorated transverse bands on the leaves of the thermo-sensitive rice line 1103s (Oryza sativa ssp. indica) was induced by cold shock and the change of leaf color coincided with the change of chlorophyll contents. Utrastructural observation observation revealed that the chloroplast structurein the yellow part degenerated, i. e., the number of stocs in granum abnormally decreased, thylakoid systemwas disintegrated and replaced by few single thylakoid, and then the whole structure of some chloroplast became vesicle-like structure with high electronic density. Nonetheless, in the green zone of the green-yellowbanded leaf, there were slight decrease in the number granum thylakoids, disothered grana arrangement in thechloroplast, and aggregation of osmiophile globule. However, it was found that these structural alternationswere reversable in the process of recovery of the yellow part of the leaves into green, and the chloroplast structure renewed normally. It might be concluded that the character of green-yellow bands induced by cold shockwas consequent upon a revere process of degeneration and regeneration.