Rajendran Karthika, Tester Mark, Roy Stuart J
The Australian Centre for Plant Functional Genomics, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia.
Plant Cell Environ. 2009 Mar;32(3):237-49. doi: 10.1111/j.1365-3040.2008.01916.x. Epub 2008 Nov 25.
Salinity stress is a major factor inhibiting cereal yield throughout the world. Tolerance to salinity stress can be considered to contain three main components: Na(+) exclusion, tolerance to Na(+) in the tissues and osmotic tolerance. To date, most experimental work on salinity tolerance in cereals has focused on Na(+) exclusion due in part to its ease of measurement. It has become apparent, however, that Na(+) exclusion is not the sole mechanism for salinity tolerance in cereals, and research needs to expand to study osmotic tolerance and tissue tolerance. Here, we develop assays for high throughput quantification of Na(+) exclusion, Na(+) tissue tolerance and osmotic tolerance in 12 Triticum monococcum accessions, mainly using commercially available image capture and analysis equipment. We show that different lines use different combinations of the three tolerance mechanisms to increase their total salinity tolerance, with a positive correlation observed between a plant's total salinity tolerance and the sum of its proficiency in Na(+) exclusion, osmotic tolerance and tissue tolerance. The assays developed in this study can be easily adapted for other cereals and used in high throughput, forward genetic experiments to elucidate the molecular basis of these components of salinity tolerance.
盐分胁迫是抑制全球谷物产量的主要因素。对盐分胁迫的耐受性可被认为包含三个主要组成部分：钠离子排斥、组织对钠离子的耐受性和渗透耐受性。迄今为止，大多数关于谷物耐盐性的实验工作都集中在钠离子排斥上，部分原因是其易于测量。然而，很明显，钠离子排斥并不是谷物耐盐性的唯一机制，研究需要扩展到对渗透耐受性和组织耐受性的研究。在此，我们开发了一些测定方法，主要利用市售的图像捕获和分析设备，对12个一粒小麦种质的钠离子排斥、钠离子组织耐受性和渗透耐受性进行高通量定量分析。我们表明，不同的品系利用这三种耐受机制的不同组合来提高它们的总耐盐性，并且观察到植物的总耐盐性与其在钠离子排斥、渗透耐受性和组织耐受性方面的能力总和之间存在正相关。本研究中开发的测定方法可以很容易地应用于其他谷物，并用于高通量正向遗传学实验，以阐明这些耐盐性组成部分的分子基础。
