Kumar Gautam, Purty Ram Singh, Sharma Mahaveer P, Singla-Pareek Sneh L, Pareek Ashwani
Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.
J Plant Physiol. 2009 Mar 15;166(5):507-20. doi: 10.1016/j.jplph.2008.08.001. Epub 2008 Sep 16.
Significant inter- and intra-specific variation for salt tolerance exists within the family Brassicaceae, which may be explored for dissecting genetic determinants of the salinity response in crops belonging to this family. Availability of contrasting cultivars for salinity response in crop species, such as Brassica, is highly advantageous for obvious reasons. Our analysis has indicated usefulness of available local germplasm (diploid and amphidiploid) in this endeavor. Assessments carried out employing suitable morphological, physiological and biochemical parameters in these cultivars reconfirm established fact related to 'in-general' better adaptability of amphidiploid species over diploid ones. In our study, the salinity-tolerant amphidiploid Brassica juncea cv CS52 (AB genome) exhibited sharp contrast in salinity response as compared to the sensitive diploid species Brassica nigra (B genome). The differences included effects of salinity on overall growth, electrolyte leakage, proline accumulation and the K(+)/Na(+) ratio (P0.01). Correlating well with relative stress tolerance of these Brassica cultivars, our studies on relative transcript abundance for salt overly sensitive (SOS) pathway orthologues also exhibited contrasting patterns of transcript accumulation. Transcript accumulation pattern for various SOS members after 24h of salinity stress in various cultivars showed strong positive correlation with these parameters (r0.4). Clearly, there is a need to carry out in-depth analysis to explore the suitability of these contrasting cultivars to search for genetic determinant(s) of salt tolerance among Brassica species. We propose that these contrasting Brassica cultivars can serve as suitable dicot crop models for elucidating stress-relevant genetic determinants in genome-level analysis.
十字花科内存在显著的种间和种内耐盐性差异，可利用这些差异剖析该科作物盐度响应的遗传决定因素。出于显而易见的原因，在作物品种（如甘蓝型油菜）中获得对盐度响应具有差异的品种非常有利。我们的分析表明，现有的本地种质（二倍体和双二倍体）在这方面很有用。利用这些品种合适的形态、生理和生化参数进行的评估再次证实了一个既定事实，即一般而言，双二倍体物种比二倍体物种具有更好的适应性。在我们的研究中，耐盐双二倍体芥菜型油菜品种CS52（AB基因组）与敏感的二倍体物种黑芥（B基因组）相比，在盐度响应上表现出明显差异。这些差异包括盐度对整体生长、电解质渗漏、脯氨酸积累和K(+)/Na(+)比值的影响（P<0.0）。与这些甘蓝型油菜品种的相对胁迫耐受性密切相关，我们对盐过度敏感（SOS）途径直系同源物的相对转录本丰度的研究也显示出转录本积累的对比模式。在不同品种中，盐胁迫24小时后各种SOS成员的转录本积累模式与这些参数呈强正相关（r>0.4）。显然，有必要进行深入分析，以探索这些对比品种在寻找甘蓝型油菜物种耐盐遗传决定因素方面的适用性。我们提出，这些对比的甘蓝型油菜品种可作为合适的双子叶作物模型，用于在基因组水平分析中阐明与胁迫相关的遗传决定因素。
