Yaish M W
Department of Biology, College of Science, Sultan Qaboos University, Muscat, Oman.
Genet Mol Res. 2015 Aug 19;14(3):9943-50. doi: 10.4238/2015.August.19.30.
Plants exposed to certain abiotic stress conditions tend to produce the amino acid proline, which acts as an active osmolyte, a metal chelator, an antioxidant, and a signaling molecule. There is increasing evidence that proline accumulates in plants due to a wide range of abiotic stress, in particular high soil salinity and drought. Therefore, proline content is often used as a marker-assisted breeding tool aimed at improving drought and salinity tolerance. In this study, it was investigated whether proline accumulation in date palm (Phoenix dactylifera L.) seedlings occurs solely due to high salinity and drought stresses or due to other unspecified abiotic stresses, including salinity and salinity shock, drought, extreme temperatures, and abscisic acid. The free proline assays revealed that this amino acid over-accumulated in the roots and leaves of each stress-treated plant, and was remarkably high when leaves were exposed to suboptimum temperatures and salinity stress. These results indicate that the production of proline is a common response to various abiotic stresses and its differential accumulation cannot be used as a molecular marker in date palm breeding programs aimed at improving drought or salinity tolerance traits in date palms. This conclusion is consistent with the theory that the molecular outcomes of abiotic stresses are often non-specific.
暴露于某些非生物胁迫条件下的植物往往会产生氨基酸脯氨酸，脯氨酸可作为一种活性渗透剂、金属螯合剂、抗氧化剂和信号分子。越来越多的证据表明，由于多种非生物胁迫，特别是高土壤盐分和干旱，脯氨酸会在植物中积累。因此，脯氨酸含量常被用作一种标记辅助育种工具，旨在提高植物对干旱和盐分的耐受性。在本研究中，研究了海枣（Phoenix dactylifera L.）幼苗中脯氨酸的积累是否仅由高盐度和干旱胁迫引起，还是由其他未明确的非生物胁迫引起，包括盐度和盐度冲击、干旱、极端温度和脱落酸。游离脯氨酸测定结果表明，这种氨基酸在每种胁迫处理植物的根和叶中过度积累，当叶片暴露于次适温度和盐胁迫时，脯氨酸含量显著升高。这些结果表明，脯氨酸的产生是对各种非生物胁迫的常见反应，其差异积累不能用作海枣育种计划中的分子标记，该育种计划旨在改善海枣的耐旱或耐盐性状。这一结论与非生物胁迫的分子结果往往是非特异性的这一理论一致。
