Department of Biochemistry, University of Nebraska, Lincoln, Nebraska 68583-0718.
Plant Physiol. 1988 Mar;86(3):773-7. doi: 10.1104/pp.86.3.773.
Mutants of the unicellular, green alga Chlamydomonas reinhardtii were recovered by screening for the absence of photoautotrophic growth at 35 degrees C. Whereas nonconditional mutants required acetate for growth at both 25 and 35 degrees C, the conditional mutants have normal photoautotrophic growth at 25 degrees C. The conditional mutants consisted of two classes: (a) Temperature-sensitive mutants died under all growth conditions at 35 degrees C, but (b) temperature-sensitive, acetate-requiring mutants were capable of heterotrophic growth at 35 degrees C when supplied with acetate in the dark. The majority of mutants within the latter of these two classes had defects in photosynthetic functions. These defects included altered pigmentation, reduced whole-chain electron-transport activity, reduced ribulosebis-phosphate carboxylase activity, or pleiotropic alterations in a number of these photosynthetic components. Both nuclear and chloroplast mutants were identified, and a correlation between light-sensitive and photosynthesis-deficient phenotypes was observed.
单细胞绿藻莱茵衣藻的突变体是通过筛选在 35°C 时缺乏光自养生长而恢复的。虽然非条件突变体在 25°C 和 35°C 时都需要乙酸盐才能生长，但条件突变体在 25°C 时具有正常的光自养生长。条件突变体包括两类：(a)温度敏感突变体在 35°C 下的所有生长条件下都会死亡，但(b)温度敏感、需要乙酸盐的突变体在黑暗中提供乙酸盐时能够在 35°C 下进行异养生长。这两类中的大多数突变体在光合作用功能上都有缺陷。这些缺陷包括色素改变、全链电子传递活性降低、核酮糖 1,5-二磷酸羧化酶活性降低，或这些光合作用成分中的许多发生多效改变。鉴定出了核和叶绿体突变体，并观察到光敏感和光合作用缺陷表型之间存在相关性。
