BIOCHEMICAL-CHANGES THAT OCCUR DURING SENESCENCE OF WHEAT LEAVES .1. BASIS FOR THE REDUCTION OF PHOTOSYNTHESIS
BIOCHEMICAL-CHANGES THAT OCCUR DURING SENESCENCE OF WHEAT LEAVES .1. BASIS FOR THE REDUCTION OF PHOTOSYNTHESIS
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DOI：
10.1104/pp.70.6.1641
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发表时间：
1982-01-01
期刊：
影响因子：
7.4
通讯作者：
MORELAND, DE
中科院分区：
文献类型：
--
作者：
CAMP, PJ;HUBER, SC;MORELAND, DE
小麦(T.aestivum L.cv.)营养叶和旗叶的光合酶活性和光化学过程随衰老而变化。Roy)。基质酶的活性先于光化学活性开始下降。总体而言，可溶性总蛋白、核酮糖-1，5-二磷酸羧化酶和NADP-三糖-磷酸脱氢酶活性的下降与叶片叶绿素(Chl)、叶片光合作用和光合电子传递活性平行且早于叶绿素(Chl)。根据3条证据，叶片似乎失去了整个叶绿体，而不是所有叶绿体的普遍降解。按面积计算的电子传输活性下降的时间比按Chl计算的相同数据要早得多。成熟组织和衰老组织的每个叶绿体的Chl含量相似，在550 nm(光散射)/单位Chl处的吸光度基本保持不变，直到衰老结束。然而，叶绿体在失去之前确实经历了一些修饰(例如，基质酶活性的丧失)，但叶片光合作用的降低显然是由整个叶绿体的丧失引起的。
Changes in activities of photosynthetic enzymes and photochemical processes were followed with aging of vegetative and flag leaves of wheat (T. aestivum L. cv. Roy). Activities of stromal enzymes began to decline prior to photochemical activities. In general, total soluble protein and the activities of ribulose-1,5-bisphosphate carboxylase and NADP-triose-phosphate dehydrogenase declined in parallel and at an earlier age than leaf chlorophyll (Chl), leaf photosynthesis and photosynthetic electron transport activity. Leaves appeared to lose whole chloroplasts as opposed to a general degradation of all chloroplasts based on 3 lines of evidence. Electron transport activity calculated on an area basis declined much earlier than the same data expressed on a Chl basis. Chl content per chloroplast was similar for mature and senescent tissue and the absorbance at 550 nm (light scattering)/unit of Chl remained essentially constant until the end of senescence. Chloroplasts did, however, undergo some modifications before they were lost (e.g., loss of stromal enzyme activites), but the reduction in leaf photosynthesis was apparently caused by a loss of whole chloroplasts.