Effect of high irradiance and high temperature on chloroplast composition and structure of Dioscorea zingiberensis.

摘要

High irradiance (HI, 1000 micro mol m-1 s-1 for 1.5 h) and high temperature (HT, 32 degrees C) increased in chloroplasts of D. zingiberensis the content of monogalactosyldiacylglycerol (MGDG) and decreased the contents of digalactosyldiacylglycerol (DGDG), sulfoquinovosyldiacylglycerol (SQDG), and phosphatidylinositol (PI). HI and HT accelerated the transformation of DGDG to MGDG. The contents of unsaturated fatty acids in chloroplasts increased, while those of saturated fatty acids decreased. The contents of total carotenoids, neoxanthin, violaxanthin, lutein, and beta -carotene increased first, then decreased. The content of chlorophyll decreased. HI caused the unfolding of thylakoids that was not resumed after a 72-h recovery.