芦苇叶中Rubisco对干旱生境的响应

EFFECT OF DROUGHT STRESS ON STRUCTURE CHARACTERISTICS OF RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE IN PHRAGMITES COMMUNIS

从分布于甘肃省河西走廊的沼泽芦苇和沙丘芦苇叶中提纯的Ｒｕｂｉｓｃｏ，大、小亚基分子量无明显变化，但沙丘芦苇与沼泽芦苇相比较，Ｒｕｂｉｓｃｏ的氨基酸组成中，亲水性氨基酸相对含量增加，疏水性氨基酸相对含量减少，酶分子的疏水性降低，且酶分子中可被ＰＣＭＢ滴定的ＳＨ基数仅为沼泽芦苇的５０％。这说明，芦苇在长期适应沙丘干旱生境过程中，其Ｒｕｂｉｓｃｏ无论在结构与功能上，均发生有适应性的改变。

There was no change on molccular weight of small and large subunits of Rubisco purifiedfrom Swamp-reed and Sand dune-reed(Phragmites communis)distributed in the Hexi Corri-dor, Gansu Province. There was different amino acid composition in Rubisco purified from differ-ent habitat reeds plant. Drought stress induce a higher hydrophility and a lower average hy-drophobicity of Rubisco. The Rubisco purified from Sand dune-reed plants contained about 50%of titratable SH groups as compared with that the Swamp-reed plants. The results indicate thatSand dune-reed plants,drought induces conformational changes and gene expression changes inRubisco which may be responsible for its adaptation to drought stress,it also indicates that it issuitable to conside the Swamp-reed and Sand dune-reed as two ecotypes.