Differences in the physiological responses of Rht13 and rht wheat lines to short-term osmotic stress
Differences in the physiological responses of Rht13 and rht wheat lines to short-term osmotic stress
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DOI：
10.1007/s42976-020-00012-5
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发表时间：
2020-01
影响因子：
1.6
通讯作者：
J. Yan;N. Zhang;X. Wang;S. Zhang
中科院分区：
文献类型：
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作者：
J. Yan;N. Zhang;X. Wang;S. Zhang
赤霉素不敏感矮秆基因Rht-B1和Rht-D1 b已被广泛应用于降低株高、提高产量和改善收获指数。赤霉素反应性矮秆基因，如Rht 13，具有小麦改良的潜力，但没有用于商业育种。本研究以Rht 13的Magnif M1和Rht 8的晋麦47为亲本，通过杂交选育获得了一组不同株高的重组自交系。以Rht 13和rht为对照，在10%PEG模拟的水培条件下，研究了Rht 13对小麦抗旱性的影响。在渗透胁迫下，Rht 13幼苗的蒸腾速率显著低于Rht品系。Rht 13的光合速率、叶片失水速率和叶片相对含水量均高于对照。在研究这些差异的原因时，我们发现Rht 13系的根系可以通过渗透调节和调节质膜水通道蛋白（TaPIPs）的表达来减轻根系导度（Lp）的下降。在短期渗透胁迫下，Rht 13幼苗的蒸腾速率降低，地上部水分损失明显减少，根系吸水能力增强，因此Rht 13幼苗比Rht幼苗更有效地维持了整体水分平衡。这些发现表明，矮秆等位基因是一个潜在的候选小麦育种计划，旨在提高性能在干旱和半干旱地区。
GA-insensitive dwarfing genes e.g.Rht-B1bandRht-D1bhave been widely used to reduce plant height, increase grain yield and improve harvest index values. GA-responsive dwarfing genes, such asRht13, have potential for wheat improvement but are not used in commercial breeding. Here, a set of recombinant inbred lines (RILs) of varying height was developed from a cross ofRht13-containing Magnif M1 andRht8-containing Jinmai 47. These RILs (Rht13andrht) were used to evaluate the effects ofRht13on wheat drought resistance under hydroponics conditions simulated by polyethylene glycol-6000 (10% PEG). Under osmotic stress,Rht13seedlings showed significantly lower transpiration rates thanrhtlines. TheRht13seedlings also had relatively higher photosynthetic rates and lower leaf water loss rates and higher leaf relative water content thanrhtlines. While investigating the reasons underlying these differences, we found that theRht13lines’ root system could reduce the decrease in root hydraulic conductance (Lp) via osmotic adjustment and via modulating the expression of plasma membrane aquaporins (TaPIPs). Because of the reduced transpiration rate, severely reduced shoot water loss and improved water uptake ability of roots under short-term osmotic stress, theRht13 seedlings maintained their overall water balance more effectively than did therhtseedlings. These findings demonstrate that the dwarfing allele is a potential candidate for wheat breeding programs aiming to improve performance in arid and semi-arid regions.