Chourey Karuna, Ramani Saradha, Apte Shree Kumar
Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085, India.
J Plant Physiol. 2003 Oct;160(10):1165-74. doi: 10.1078/0176-1617-00909.
Germination and subsequent hydroponic growth under salt stress (100 mmol/L NaCl) triggered an accumulation of six major stress proteins and resulted in a growth arrest of young seedlings of rice (Oryza sativa L.) cv. Bura Rata. Based on two-dimensional electrophoretic resolution, partial amino acid sequencing and immunodetection techniques, four of the salt stress-induced polypeptides were identified as LEA proteins. Under all experimental conditions wherein seedlings exhibited superior halotolerance, salt stress-induced LEA proteins were expressed at low levels. In contrast, accumulation of LEA proteins was found associated with growth arrest. When returned to non-saline media, seedlings stressed with salt for four days recovered immediately. Longer exposure to 100 mmol/L NaCl, however, progressively delayed recovery and reduced the number of seedlings which could recover from salt stress. Recovery from salt stress was consistently accompanied by degradation of the salt stress-induced LEA proteins. The results of this study show that LEA proteins accumulate during the salinity-triggered growth arrest of young Bura Rata seedlings and are mobilised during the recovery of seedlings from salinity stress.
在盐胁迫（100 mmol/L NaCl）下的萌发及随后的水培生长引发了六种主要胁迫蛋白的积累，并导致水稻（Oryza sativa L.）品种Bura Rata幼苗生长停滞。基于二维电泳分离、部分氨基酸测序和免疫检测技术，四种盐胁迫诱导的多肽被鉴定为胚胎发育晚期丰富蛋白（LEA蛋白）。在幼苗表现出较强耐盐性的所有实验条件下，盐胁迫诱导的LEA蛋白表达水平较低。相反，发现LEA蛋白的积累与生长停滞有关。当回到无盐培养基中时，经盐胁迫处理四天的幼苗立即恢复。然而，长时间暴露于100 mmol/L NaCl会逐渐延迟恢复并减少能够从盐胁迫中恢复的幼苗数量。从盐胁迫中恢复始终伴随着盐胁迫诱导的LEA蛋白的降解。本研究结果表明，LEA蛋白在盐胁迫引发的Bura Rata幼苗生长停滞期间积累，并在幼苗从盐胁迫中恢复时被调动。
