The 70-kDa heat shock proteins (HSP70s) are a conserved class of chaperones that play critical roles during the normal life cycle of plants. HSP70s are particularly involved in the regulation of biotic and abiotic stress responses. In this paper, the potential roles of this protein were investigated. A reverse genetic approach was employed for transient silencing of hsp70 gene in tomato (Solanum lycopersicum L.) to evaluate different growth and physiological parameters under normal conditions and during the response to drought stress. A combined ANOVA (analysis of variance) and HCA (hierarchical clustering analysis) showed that hsp70 silencing led to severe growth retardation and mortality, significant membrane damage and leakage, decline in relative water content, low rate of pigment accumulation, and reduced antioxidant enzyme activity under normal and drought stress conditions. Among the different parameters, proline was the only trait that was unaffected by gene silencing and accumulated by similar amounts to that of nonsilent plants. In conclusion, HSP70 played critical roles in maintaining the cellular homeostasis of plants during adaptation to drought and under normal plant life conditions. It was speculated that proline was, to some extent, involved in improving the loss of protein folding or function resulting from HSP70 deficiency, and played a crucial role in the adaptation of plants on exposure to stress.

70-kDa 热休克蛋白 (HSP70s) 是一类保守的伴侣蛋白，在植物的正常生命周期中发挥关键作用。HSP70s 特别参与生物和非生物应激反应的调节。在本文中，研究了这种蛋白质的潜在作用。采用反向遗传方法对番茄 ( Solanum lycopersicum L.) 中的hsp70基因进行瞬时沉默，以评估正常条件下和干旱胁迫响应期间的不同生长和生理参数。组合的 ANOVA（方差分析）和 HCA（层次聚类分析）表明hsp70在正常和干旱胁迫条件下，沉默导致严重的生长迟缓和死亡、显着的膜损伤和渗漏、相对含水量下降、色素积累率低以及抗氧化酶活性降低。在不同的参数中，脯氨酸是唯一不受基因沉默影响的性状，其积累量与非沉默植物相似。总之，HSP70 在适应干旱和正常植物生活条件下在维持植物细胞稳态方面发挥了关键作用。据推测，脯氨酸在一定程度上参与了改善HSP70缺乏导致的蛋白质折叠或功能丧失，并在植物对胁迫的适应中发挥了至关重要的作用。