Developmental Plasticity of Rice Root System Grown under Mild Drought Stress Condition with Shallow Soil Depth; Comparison between Nodal and Lateral roots
Developmental Plasticity of Rice Root System Grown under Mild Drought Stress Condition with Shallow Soil Depth; Comparison between Nodal and Lateral roots
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DOI：
10.1080/1343943x.2015.1128094
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发表时间：
2016-01-01
影响因子：
2.5
通讯作者：
Yamauchi, Akira
中科院分区：
文献类型：
--
作者：
Kameoka, Emi;Suralta, Roel Rodriguez;Yamauchi, Akira
水稻根系发育的可塑性是水稻适应轻度干旱的一个重要性状。然而，由于可塑性增强RSD可能并不总是一个单一的功能，促进侧根（LR）的生产，但也节根（NR）的发展的综合反应。在这项研究中，我们的目的是评估轻度干旱强度对NR和LR的发展，以及它们对整个RSD的贡献的影响。我们使用了6个基因型，包括KDML105（籼稻，低地适应），一个高侧根能力的基因型。植物生长到抽穗期或成熟期，在土壤深度有限（20 cm）的土壤下生长两年，假设存在硬土层，并在线源喷洒系统产生的不同水分梯度下生长。干旱强度对NR和LR发育的影响一般不同。在这两年中，所有基因型表现出最高的LR发展在轻度干旱胁迫强度。但在KDML105等基因型中，NR发育仅在有限的土壤水分范围内维持，比LR可塑性表达的土壤水分范围更窄、更湿润。此外，只有当NR和LR同时提升或维持时，整个RSD才得以维持。这些结果表明，NR有较小的可塑性比LR在响应干旱和LR发展的整个RSD的贡献是依赖于土壤水分和节生根能力。
The plasticity in root system development (RSD) is a key trait for the adaptation of rice to mild drought. However, the enhanced RSD due to the plasticity may not be always a sole function of promoted lateral root (LR) production, but also of the integrated responses of nodal root (NR) development. In this study, we aimed to evaluate the effects of mild drought intensities on the development of the NR and LR, and their contribution to the entire RSD. We used six genotypes including KDML105 (indica, lowland adapted), a high lateral rooting ability genotype. The plants were grown up to heading or maturity stage for two years under soil with limited soil depth (20 cm) assuming the presence of the hardpan and at different moisture gradients generated by the line source sprinkler system. The effects of drought intensities generally differed between the development of NR and LR. In both years, all genotypes showed highest LR development under mild drought stress intensities. However, in some genotypes including KDML105, NR development was maintained in a limited soil moisture range only, which was narrower and wetter than that in which LR plasticity was expressed. Furthermore, the entire RSD was maintained only when both the NR and LR were simultaneously promoted or maintained. These results suggest that the NR have less plasticity than the LR in response to drought and the contribution of the plasticity in LR development to the entire RSD is dependent on both the soil moisture and nodal rooting ability.