温度对水稻突变体W1叶色及叶绿素生物合成的影响

EFFECTS OF TEMPERATURE ON LEAF COLOR AND CHLOROPHYLL BIOSYNTHESIS OF RICE MUTANT W1

本文研究了温度对水稻突变体W1叶色及叶绿素 (Chl)生物合成的影响。W1是温敏型叶色突变体 ,叶色转变的临界温度约为 2 3℃。在高温下 ,突变体W1的Chl和类胡萝卜素 (Caro)含量与对照无显著的差异 ,幼苗呈绿色 ;低温 (1 5～ 2 0℃ )下W1的Chl和类胡萝卜素 (Caro)含量明显较低 ,表现白化。突变体W1白化苗中的Chla和Chlb含量同时下降 ,Caro Chl的比值增大 ,说明该突变体属于不是由Caro降低而导致的总叶绿素缺陷型。白化苗中Chl生物合成的中间产物原叶绿素 (酸 ) (Pchl)、镁原卟啉 (Mg proto)、原卟啉IX(ProtoIX)含量减少 ,而δ 氨基酮戊酸 (ALA)和胆色素原(PBG)大量积累 。

Effects of temperature on leaf color and chlorophyll (Chl)biosynthesis of mutant W1 in rice were studied.The mutant W1 belonged to a temperature sensitive type and the critical temperature for the change of leaf color was about 23℃.Under high temperature the seedlings of the mutant W1 were green and there was no significant difference between W1 and 2177S(CK)in the content of Chl and Caro.However,under low temperatures(15～20℃)the leaves of W1 were albino with very little amount of Chl and Caro.The decrease of Chl a and Chl b at the same time and the increase in the ratio of Caro/Chl in albino seedlings showed that the mutant W1 belonged to the total Chl deficient type that was not caused by the decrease of Caro content.The content of intermediates such as protochlorophyll (Pchl),Mg protoporphyrin(Mg proto)and protoporphyrin IX(proto IX)were reduced and δ aminolevulinc acid(ALA) and porphohilinogen(PBG)were markedly accumulated in albino seedlings of W1,which proved that there was a blockage in the formation of uroporphyrinogen or coproporphyrinogen during Chl biosynthesis under lower temperature.