ABSTRACT

The role of folic acid (FA) or its derivatives (folates) in plant responsiveness to drought stress is still unclear. Here we investigated the effect of foliar application of FA (50, 100 and, 150 µM/l) on snap beans (Phaseolus vulgaris L.) grown under two levels of surface drip irrigation (100% and 70% of water requirements) in two successive seasons of 2018 and 2019. The results showed that deficit irrigation led to a significant decrease in plant growth, leaf relative water content (RWC) and cell membrane stability index (CMSI). These responses negatively affected green pod yield and quality indicators in terms of total soluble solids (TSS) and protein. Conversely, malondialdehyde (MDA), proline, free amino acids (FAA), total soluble sugars, antioxidant enzymes (SOD, CAT and POX) and the fibres of green pods were significantly increased. The regression analysis revealed that all investigated osmolytes and antioxidant enzymes were negatively and significantly correlated with RWC in both seasons. Under deficit irrigation, plants treated with 150 µM FA had higher water use efficiency (WUE) by 29.2% and 16.6% over the FA-untreated plants in both seasons, respectively. The foliar application of 150 µM FA significantly improved most studied traits and could be recommended as a protective agent against deficit irrigation.

摘要

叶酸（FA）或其衍生物（叶酸）在植物对干旱胁迫的响应中的作用仍不清楚。在这里，我们研究了叶面施用FA（50、100和150 µM / l）对绿豆（菜豆）的影响。L.）在2018年和2019年连续两个季节在两个水平的地面滴灌（需水量的100％和70％）下生长。结果表明，亏水灌溉导致植物生长，叶片相对含水量（ RWC）和细胞膜稳定性指数（CMSI）。这些反应对总可溶性固形物（TSS）和蛋白质的绿色豆荚产量和质量指标产生了负面影响。相反，丙二醛（MDA），脯氨酸，游离氨基酸（FAA），总可溶性糖，抗氧化酶（SOD，CAT和POX）和生豆荚的纤维显着增加。回归分析显示，所有调查的渗透压和抗氧化酶在两个季节均与RWC呈负相关且显着相关。在亏水灌溉下 在两个季节中，用150 µM FA处理过的植物的水分利用效率（WUE）分别比未经FA处理的植物高29.2％和16.6％。叶面喷施150 µM FA可以显着改善大多数研究的性状，并建议将其作为防止亏水的保护剂。