2 SWEETCLOVER (MELILOTUS-ALBA DESR) MUTANTS TEMPERATURE-SENSITIVE FOR CHLOROPHYLL EXPRESSION
2 SWEETCLOVER (MELILOTUS-ALBA DESR) MUTANTS TEMPERATURE-SENSITIVE FOR CHLOROPHYLL EXPRESSION
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DOI：
10.1104/pp.103.4.1123
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发表时间：
1993-12-01
期刊：
影响因子：
7.4
通讯作者：
MARKWELL, J
中科院分区：
文献类型：
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作者：
BEVINS, MA;MADHAVAN, S;MARKWELL, J
非等位基因三叶草(Melilotus alba Desr.)突变株U371(CH10/CH10)和U372(CH11/CH11)来源于亲本株U389(+/+)。U389菌株在17或26摄氏度的温度下生长，会产生外观通常为绿色的植物。26℃下生长的U371和U372突变体植株叶绿素(Chl)轻度到中度缺乏，Chlb/a比值降低。在17℃下生长的突变体导致植株严重缺乏Chla，除紫黄质外，类胡萝卜素水平显著降低，捕光系统II的捕光复合体Chlb或脱辅基蛋白的含量可以忽略不计。如果在17℃下生长的突变植株被转移到26℃，在接下来的20 d内，每鲜重Chl的数量将增加5倍，Chlb/a比率和捕光复合脱辅基蛋白的表达都将逐渐增加。对U371突变体在温度诱导的绿化过程中的研究表明，叶绿体超微结构和叶片碳同位素分馏的逐渐变化与Chl的增加平行。在突变体中观察到的叶片碳同位素分馏的变化表明，除了已知的各种非生物因素的影响外，结构和代谢内部因素也可以影响二氧化碳固定的限制是在扩散水平还是在羧化水平。在这些突变体和类似突变体中，这种温度引发的渐进式绿化不仅可以用来阐明光合作用装置的生物合成和组装，还可以用来阐明光合作用过程中光驱动的能量产生对总碳同位素分馏的影响等生理现象。
The nonallelic sweetclover (Melilotus alba Desr.) mutants U371 (ch10/ch10 genotype) and U372 (ch11/ch11 genotype) are derived from the U389 (+/+ genotype) parental strain. Growth of the U389 strain at a temperature of 17 or 26-degrees-C results in plants normally green in appearance. The U371 and U372 mutant plants grown at 26-degrees-C are slightly to moderately chlorophyll (Chl) deficient and have decreased Chl b/a ratios. Growth of the mutants at 17-degrees-C results in plants severely deficient in Chl a, with markedly reduced levels of carotenoids except for violaxanthin, and with negligible amounts of Chl b or apoproteins for the light-harvesting complex of photosystem II. If mutant plants grown at 17-degrees-C are transferred to 26-degrees-C, during the next 20 d the amount of Chl per fresh weight will increase 5-fold and both the Chl b/a ratio and the expression of the light-harvesting complex apoproteins will progressively increase. Studies of the U371 mutant during the temperature-induced greening demonstrate progressive changes in chloroplast ultrastructure and leaf carbon isotope fractionation that parallel the increases in Chl. Changes observed in the leaf carbon isotope fractionation in the mutant suggest that, in addition to the already known effects of various abiotic factors, structural and metabolic internal factors can also influence whether the limitation in CO2 fixation is at the level of diffusion or carboxylation. Such temperature-initiated progressive greening in these and similar mutants may make them useful tools to elucidate not only the biosynthesis and assembly of the photosynthetic apparatus, but also physiological phenomena such as the influence of light-driven energy production on the overall carbon isotope fractionation during photosynthesis.