Department of Structural Biology, Faculty of Earth and Life Sciences, Vrije Universiteit, Amsterdam, The Netherlands.
PLoS One. 2013;8(3):e60183. doi: 10.1371/journal.pone.0060183. Epub 2013 Mar 22.
Potato (Solanum tuberosum) is a major crop world-wide and the productivity of currently used cultivars is strongly reduced at high soil salt levels. We compared the response of six potato cultivars to increased root NaCl concentrations. Cuttings were grown hydroponically and treated with 0 mM, 60 mM and 180 mM NaCl for one week. Growth reduction on salt was strongest for the cultivars Mozart and Mona Lisa with a severe senescence response at 180 mM NaCl and Mozart barely survived the treatment. The cultivars Desiree and Russett Burbank were more tolerant showing no senescence after salt treatment. A clear difference in Na(+) homeostasis was observed between sensitive and tolerant cultivars. The salt sensitive cultivar Mozart combined low Na(+) levels in root and stem with the highest leaf Na(+) concentration of all cultivars, resulting in a high Na(+) shoot distribution index (SDI) for Mozart as compared to Desiree. Overall, a positive correlation between salt tolerance and stem Na(+) accumulation was found and the SDI for Na(+) points to a role of stem Na(+) accumulation in tolerance. In stem tissue, Mozart accumulated more H2O2 and less proline compared to the tolerant cultivars. Analysis of the expression of proline biosynthesis genes in Mozart and Desiree showed a clear reduction in proline dehydrogenase (PDH) expression in both cultivars and an increase in pyrroline-5-carboxylate synthetase 1 (P5CS1) gene expression in Desiree, but not in Mozart. Taken together, current day commercial cultivars show promising differences in salt tolerance and the results suggest that mechanisms of tolerance reside in the capacity of Na(+) accumulation in stem tissue, resulting in reduced Na(+) transport to the leaves.
马铃薯（Solanum tuberosum）是世界范围内的主要作物，目前使用的品种在高土壤盐度下的生产力严重降低。我们比较了六个马铃薯品种对增加根际 NaCl 浓度的反应。插条在水培中生长，并在 0 mM、60 mM 和 180 mM NaCl 下处理一周。在 180 mM NaCl 下，品种莫扎特（Mozart）和莫娜丽莎（Mona Lisa）的生长受盐抑制最为严重，出现严重衰老，而莫扎特（Mozart）几乎无法在处理后存活。品种德西蕾（Desiree）和 Russett Burbank 更耐盐，盐处理后无衰老现象。在敏感和耐盐品种之间观察到明显的钠离子（Na+）稳态差异。敏感品种莫扎特（Mozart）在根和茎中结合低 Na+水平，叶片 Na+浓度为所有品种中最高，导致莫扎特（Mozart）的 Na+地上分配指数（SDI）比德西蕾（Desiree）高。总体而言，发现盐胁迫与茎 Na+积累之间存在正相关，Na+SDI 表明茎 Na+积累在耐盐性中起作用。在茎组织中，与耐盐品种相比，莫扎特（Mozart）积累了更多的 H2O2 和较少的脯氨酸。对莫扎特（Mozart）和德西蕾（Desiree）中脯氨酸生物合成基因的表达分析表明，两种品种的脯氨酸脱氢酶（PDH）表达明显降低，而德西蕾（Desiree）中吡咯啉-5-羧酸合成酶 1（P5CS1）基因表达增加，但莫扎特（Mozart）中没有。总之，目前的商业品种在耐盐性方面表现出有希望的差异，结果表明，耐盐机制存在于茎组织中 Na+积累的能力，从而减少 Na+向叶片的运输。
