茄未成熟叶与衰老叶叶绿体超微结构比较研究

Ultrastructural changes to chloroplasts in leaves of eggplant caused by senescence

为揭示叶衰老对茄叶叶绿体超微结构的影响,用透射电子显微技术对茄未成熟叶和衰老叶叶肉细胞叶绿体进行比较研究。结果表明:未成熟叶叶绿体类囊体染色深,基粒柱状,许多基粒类囊体向基质中延伸,基粒之间由基质类囊体连接,基质中有大量淀粉和少量质体小球,小球体积小,直径0.1μm以下;衰老叶叶绿体类囊体染色较浅,基粒球状,基粒类囊体向基质中的延伸减少,基质类囊体减少,淀粉减少,质体小球数量增多、体积增大,直径可达0.9μm,基质中有酚类物质积累。显然,叶衰老引起茄叶肉细胞叶绿体类囊体膜组成改变,基质类囊体解体,淀粉减少而质体小球增加,并引起酚类物质积累。

In order to determine the effect of senescence on the structure and function of chloroplasts in leaf mesophyll cells of eggplant（Solanum melongena Linn.）,chloroplasts in immature and senescing leaves were comparatively studied by means of electron microscopy.Chloroplasts in the young leaf mesophyll cells contain cylindrical grana that are connected by stroma thylakoids,rich starch grains,and a few small plastoglobuli that are less than 0.1 μm in diameter.The thylakoids are stained more strongly.However,in the chloroplasts in the old leaves,grana become spherical,thylakoids are stained weakly,stroma thylakoids become less in number,starch grains are reduced or disappeared,plastoglobuli increase in number and size with diameter up to 0.9 μm,and phenolic accumulation appears.It is suggested that leaf senescence of eggplant induces change to thylakoid membrane constituents,inhibits starch accumulation,promotes plastoglobule accumulation,and stimulates phenolic accumulation.