Starch reduction in rice stems due to a lack of OsAGPL1 or OsAPL3 decreases grain yield under low irradiance during ripening and modifies plant architecture
Starch reduction in rice stems due to a lack of OsAGPL1 or OsAPL3 decreases grain yield under low irradiance during ripening and modifies plant architecture
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DOI：
10.1071/fp13105
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发表时间：
2013-01-01
影响因子：
3
通讯作者：
Aoki, Naohiro
中科院分区：
文献类型：
--
作者：
Okamura, Masaki;Hirose, Tatsuro;Aoki, Naohiro
水稻淀粉积累的研究据报道，抽穗前的茎作为非结构性碳水化合物（NSC）对于提高和稳定谷物产量是重要的。为了评估茎淀粉的重要性，我们研究了反转录转座子（Tos 17）插入水稻突变体缺乏一个基因编码的ADP-葡萄糖焦磷酸化酶（AGP）大亚基称为OsAGPL 1或OsAPL 3。突变体的茎（叶鞘和秆）中的AGP活性和淀粉含量显著降低，而叶片和胚乳中的AGP活性和淀粉含量没有显著降低。突变体叶鞘中的这种淀粉减少通过引入野生型OsAGPL 1来补充。这些结果有力地表明OsAGPL 1在茎淀粉积累中起主要作用。两年的田间试验表明，突变体植株比野生型植株矮。此外，突变体植株的分蘖数和分蘖角度均大于野生型植株，但抽穗期干重差异不显著。不遮光处理的对照区籽粒产量略低。然而，随着阴影的出现，这种差异大幅增加。因此，茎淀粉在低光照条件下的正常成熟是不可缺少的，并可能有助于维持适当的植物结构。
Starch accumulated in rice (Oryza sativa L.) stems before heading as nonstructural carbohydrates (NSCs) is reported to be important for improving and stabilising grain yield. To evaluate the importance of stem starch, we investigated a retrotransposon (Tos17) insertion rice mutant lacking a gene encoding a large subunit of ADP-glucose pyrophosphorylase (AGP) called OsAGPL1 or OsAPL3. The AGP activity and starch contents of the mutant were drastically reduced in the stem (i.e. leaf sheath and culm) but not in the leaf blade or endosperm. This starch reduction in the leaf sheaths of the mutant was complemented by the introduction of wild-type OsAGPL1. These results strongly suggest that OsAGPL1 plays a principal role in stem starch accumulation. Field experimentations spanning 2 years revealed that the mutant plants were shorter than the wild-type plants. Moreover, the tiller number and angle were larger in the mutant plants than the wild-type plants, but the dry weight at heading stage was not different. The grain yield was slightly lower in control plots without shading treatment. However, this difference increased substantially with shading. Therefore, stem starch is indispensable for normal ripening under low irradiance conditions and probably contributes to the maintenance of appropriate plant architecture.