Nitrogen resorption and protein degradation during leaf senescence in Chenopodium album grown in different light and nitrogen conditions.
Nitrogen resorption and protein degradation during leaf senescence in Chenopodium album grown in different light and nitrogen conditions.
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DOI：
10.1071/fp06307
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发表时间：
2007-06
期刊：
影响因子：
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通讯作者：
Y. Yasumura;K. Hikosaka;T. Hirose
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文献类型：
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作者：
Y. Yasumura;K. Hikosaka;T. Hirose
研究了一年生草本植物藜（Chenopodium album L.）衰老叶片对氮的吸收程度和不同蛋白库的降解率，在两种光照和氮条件下生长。氮再吸收效率（REFF;绿叶氮再吸收的比例）和熟练度（RPROF;叶片氮含量减少的水平）在不同的生长条件下变化。在叶片衰老过程中，大多数可溶性和膜蛋白降解在所有的生长条件。结构蛋白也是高度可降解的，这意味着没有特定的蛋白质库构成一个非retranslocatable N池在叶。叶片碳/氮比影响衰老过程的时间和持续时间，但它不调节蛋白质降解或N再吸收的程度。植物体内氮素的库源关系对氮素吸收有更直接的影响，在低光高氮条件下，当氮素库强度减弱时，氮素吸收受到抑制。氮再吸收，但是，没有加强在高光和低氮植物最强的N库，可能是因为它达到了上限在某个时候。我们的结论是几个生理因素的组合决定了在不同的生长条件下的N再吸收的程度。
The extent of nitrogen (N) resorption and the degradability of different protein pools were examined in senescing leaves of an annual herb, Chenopodium album L., grown in two light and N conditions. Both N resorption efficiency (REFF; the proportion of green-leaf N resorbed) and proficiency (RPROF; the level to which leaf N content is reduced by resorption) varied among different growth conditions. During leaf senescence, the majority of soluble and membrane proteins was degraded in all growth conditions. Structural proteins were also highly degradable, implying that no particular protein pool constitutes a non-retranslocatable N pool in the leaf. Leaf carbon/N ratio affected the timing and duration of senescing processes, but it did not regulate the extent of protein degradation or N resorption. Sink-source relationships for N in the plant exerted a more direct influence, depressing N resorption when N sink strength was weakened in the low-light and high-N condition. N resorption was, however, not enhanced in high-light and low-N plants with the strongest N sinks, possibly because it reached an upper limit at some point. We conclude that a combination of several physiological factors determines the extent of N resorption in different growth conditions.