Ionic relations and osmotic adjustment in durum and bread wheat under saline conditions
Ionic relations and osmotic adjustment in durum and bread wheat under saline conditions
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DOI：
10.1071/fp09051
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发表时间：
2009-01-01
影响因子：
3
通讯作者：
Shabala, Sergey
中科院分区：
文献类型：
--
作者：
Cuin, Tracey Ann;Tian, Yu;Shabala, Sergey
小麦耐盐育种传统上集中在Na+排除从地上部，但其与耐盐性的关联仍然脆弱。因此，通过研究NaCl诱导的50个基因型小麦（Triticum aestivum L.）和硬粒小麦（Triticum turgidum L.）SSP. durum）。总的来说，Na+排除从拍摄与耐盐性在这两个物种，这种排斥是更有效的面包相比，硬粒小麦。有趣的是，地上部汁液K+增加显着几乎所有的硬粒小麦和面包小麦基因型。相反，地上部总K+含量下降。我们认为，这需要增加地上部汁液K+，以提供有效的渗透调节盐条件下。硬粒小麦是能够完全调整芽汁液渗透压使用K+，Na+和Cl-，它具有固有的这些溶质的水平较高。在面包小麦中，有机渗透压调节剂必须占总茎渗透压的13%。与大麦（Hordeum vulgare L.）相反，NaCl诱导的K+从幼苗根系流出没有预测小麦耐盐性，这意味着地上部，而不是根K+的保留是重要的，在这个物种。
Wheat breeding for salinity tolerance has traditionally focussed on Na+ exclusion from the shoot, but its association with salinity tolerance remains tenuous. Accordingly, the physiological significance of shoot Na+ exclusion and maintenance of an optimal K+:Na+ ratio was re-evaluated by studying NaCl-induced responses in 50 genotypes of bread wheat (Triticum aestivum L.) and durum wheat (Triticum turgidum L. ssp. durum) treated with 150 mM NaCl. Overall, Na+ exclusion from the shoot correlated with salinity tolerance in both species and this exclusion was more efficient in bread compared with durum wheat. Interestingly, shoot sap K+ increased significantly in nearly all durum and bread wheat genotypes. Conversely, the total shoot K+ content declined. We argue that this increase in shoot sap K+ is needed to provide efficient osmotic adjustment under saline conditions. Durum wheat was able to completely adjust shoot sap osmolality using K+, Na+ and Cl-; it had intrinsically higher levels of these solutes. In bread wheat, organic osmolytes must contribute similar to 13% of the total shoot osmolality. In contrast to barley (Hordeum vulgare L.), NaCl-induced K+ efflux from seedling roots did not predict salinity tolerance in wheat, implying that shoot, not root K+ retention is important in this species.