Yamane Koji, Hayakawa Koji, Kawasaki Michio, Taniguchi Mitsutaka, Miyake Hiroshi
Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
J Plant Physiol. 2003 Nov;160(11):1319-27. doi: 10.1078/0176-1617-01180.
We investigated the effects of drought stress on the ultrastructure of chloroplasts in rice plants. After the seedlings were grown in a glasshouse for 1 month, they were treated for drought stress using two methods. One drought treatment was imposed by reducing the water supply to the plants for 1 month. The other was imposed by withholding water for 2 weeks to examine the withering process of leaves by drought stress. The ultrastructural changes of chloroplasts in bundle sheath cells were more prominent than those in mesophyll cells under both drought stress treatments. Ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) content in bundle sheath chloroplasts reduced more dramatically than in mesophyll chloroplasts by drought stress. Although a slight swelling of thylakoids was sometimes observed in bundle sheath chloroplasts in moderate stress for 1 month, the thylakoids were less affected by drought stress than chloroplast envelope. These results suggest that chloroplasts in bundle sheath cells were more sensitive to drought stress than those in mesophyll cells and the thylakoids were less damaged by drought stress compared with chloroplast envelope.
我们研究了干旱胁迫对水稻植株叶绿体超微结构的影响。幼苗在温室中生长1个月后，采用两种方法对其进行干旱胁迫处理。一种干旱处理方法是对植株减少供水1个月。另一种方法是停水2周，以研究干旱胁迫下叶片的枯萎过程。在两种干旱胁迫处理下，维管束鞘细胞中叶绿体的超微结构变化比叶肉细胞中的更为显著。干旱胁迫下，维管束鞘叶绿体中的1,5-二磷酸核酮糖羧化酶/加氧酶（rubisco）含量比叶肉叶绿体中的下降更为显著。虽然在适度胁迫1个月时，有时在维管束鞘叶绿体中观察到类囊体略有肿胀，但类囊体受干旱胁迫的影响小于叶绿体被膜。这些结果表明，维管束鞘细胞中的叶绿体比叶肉细胞中的叶绿体对干旱胁迫更敏感，与叶绿体被膜相比，类囊体受干旱胁迫的损伤较小。
