Wheat Grain Filling Is Limited by Grain Filling Capacity rather than the Duration of Flag Leaf Photosynthesis: A Case Study Using NAM RNAi Plants.
Wheat Grain Filling Is Limited by Grain Filling Capacity rather than the Duration of Flag Leaf Photosynthesis: A Case Study Using NAM RNAi Plants.
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DOI：
10.1371/journal.pone.0134947
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Uauy C
中科院分区：
文献类型：
--
作者：
Borrill P;Fahy B;Smith AM;Uauy C
有人提出，延缓叶片衰老可以延长谷类作物的灌浆历时，从而提高产量。结果表明，衰老延缓的小麦(Triticum Aestivum)NAM RNAi植株花后旗叶光合作用比对照植株多40%，但灌浆期淀粉积累的速率和持续时间相同，最终粒重相同。NAM RNAi植物中可利用的额外光合作用产物部分以果聚糖的形式储存在茎中，而对照植物的茎中果聚糖在籽粒灌浆期间被重新动员。在灌浆后期，两种类型的淀粉合成酶活性对淀粉合成均有限制作用。我们建议，为了实现延缓叶片衰老所提供的潜在产量收益，这一特性应该与增加籽粒灌浆能力相结合。
It has been proposed that delayed leaf senescence can extend grain filling duration and thus increase yields in cereal crops. We found that wheat (Triticum aestivum) NAM RNAi plants with delayed senescence carried out 40% more flag leaf photosynthesis after anthesis than control plants, but had the same rate and duration of starch accumulation during grain filling and the same final grain weight. The additional photosynthate available in NAM RNAi plants was in part stored as fructans in the stems, whereas stem fructans were remobilised during grain filling in control plants. In both genotypes, activity of starch synthase was limiting for starch synthesis in the later stages of grain filling. We suggest that in order to realise the potential yield gains offered by delayed leaf senescence, this trait should be combined with increased grain filling capacity.