Physiological basis of tolerance to complete submergence in rice involves genetic factors in addition to the SUB1 gene
Physiological basis of tolerance to complete submergence in rice involves genetic factors in addition to the SUB1 gene
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DOI：
10.1093/aobpla/plu060
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发表时间：
2014-01-01
期刊：
影响因子：
2.9
通讯作者：
Ismail, Abdelbagi M.
中科院分区：
文献类型：
--
作者：
Singh, Sudhanshu;Mackill, David J.;Ismail, Abdelbagi M.
亚洲反复发生的洪水导致农作物歉收。当植物被完全淹没几天后，产量急剧下降。传统的水稻品种占主导地位，因为它们已经获得了适度的抗洪能力，但它们本身也带来了粮食产量较低的惩罚。相比之下，现代高产品种极易受到洪水的影响。近年来，通过从高度耐淹的印度地方品种FR13A中移植耐淹基因SUB1，培育出了具有完全耐淹性的品种。本研究在野外条件下评估了三对Sub1近等基因系（NILs）以及FR13A及其两个耐淹衍生物，以评估与Sub1相关的淹没和恢复期间发生的生存和生长过程。在对照条件下，NILs的生长和生物量积累基本一致，说明SUB1对NILs的影响不明显。淹没大大降低了生物量积累，但缺乏SUB1基因型的生物量减少更大，特别是当淹没时间延长17天时。当淹水时，缺乏SUB1的品系表现出较大的伸长和较低或负的生物量积累。Sub1品系在淹水期间保持较高的叶绿素浓度，淹水后损失较少的非结构性碳水化合物（NSC）。这表明SUB1的渗入导致了淹没期间NSC的更好调节，而高的淹没前NSC对于SUB1赋予的淹没耐受性并不是必需的。在恢复过程中，缺乏SUB1基因型的叶绿素降解速度更快，任何存活植株的分蘖和叶片都出现较差和延迟的出苗现象。亚1系恢复新叶和分蘖产量较快。淹水期间，FR13A叶片伸长较慢，但积累的额外生物量比Sub1恢复快。这表明，通过结合FR13A或其他类似地方品种中存在的其他性状，进一步提高耐淹性的可能性。
Recurring floods in Asia cause poor crop establishment. Yields decline drastically when plants are completely submerged for a few days. Traditional rice cultivars predominate because they have acquired moderate tolerance to flooding but they carry the penalty of inherently lower grain yields. In contrast, modern high-yielding varieties are highly susceptible to flooding. Cultivars with tolerance to complete submergence were recently developed in the background of popular varieties by transferring the submergence tolerance gene SUBMERGENCE1 (SUB1) from the highly tolerant Indian landrace FR13A. The present study evaluated three pairs of Sub1 near-isogenic lines (NILs) together with FR13A and two of its submergence-tolerant derivatives under field conditions to assess the survival and growth processes occurring during submergence and recovery that are associated with SUB1. Under control conditions, the NILs showed similar growth and biomass accumulation, indicating that SUB1 had no apparent effects. Submergence substantially decreased biomass accumulation but with greater reduction in the genotypes lacking SUB1, particularly when submergence was prolonged for 17 days. When submerged, the lines lacking SUB1 showed greater elongation and lower or negative biomass accumulation. Sub1 lines maintained higher chlorophyll concentrations during submergence and lost less non-structural carbohydrates (NSC) after submergence. This indicates that the introgression of SUB1 resulted in better regulation of NSC during submergence and that high pre-submergence NSC is not essential for the submergence tolerance conferred by SUB1. During recovery, chlorophyll degradation was faster in genotypes lacking SUB1 and any surviving plants showed poorer and delayed emergence of tillers and leaves. Sub1 lines restored new leaf and tiller production faster. During submergence, FR13A showed not only slower leaf elongation but also accumulated extra biomass and was able to recover faster than Sub1 lines. This suggests the possibility of further improvements in submergence tolerance by incorporating additional traits present in FR13A or other similar landraces.