Rady Mostafa M, Boriek Sara H K, Abd El-Mageed Taia A, Seif El-Yazal Mohamed A, Ali Esmat F, Hassan Fahmy A S, Abdelkhalik Abdelsattar
Botany Department, Faculty of Agriculture, Fayoum University, Fayoum 63514, Egypt.
Soil and Water Science Department, Faculty of Agriculture, Fayoum University, Fayoum 63514, Egypt.
Plants (Basel). 2021 Apr 11;10(4):748. doi: 10.3390/plants10040748.
The use of growth regulators such as gibberellic acid (GA) and biostimulants, including diluted bee honey (Db-H) can improve drought tolerance in many crops, including the faba bean ( L.). Db-H contains high values of osmoprotectants, mineral nutrients, vitamins, and many antioxidants making it an effective growth regulator against environmental stress effects. Therefore, the present study was planned to investigate the potential improvement in the faba bean plant performance (growth and productivity) under full watering (100% of crop evapotranspiration (ETc)) and drought stress (60% of ETc) by foliar application of GA (20 mg L) or Db-H (20 g L). The ameliorative impacts of these growth regulators on growth, productivity, physio-biochemical attributes, nutrient status, antioxidant defense system, and phytohormones were evaluated. GA or Db-H attenuated the negative influences of drought stress on cell membrane stability, ion leakage, relative water content, nutrient status, leaf pigments related to photosynthesis (chlorophylls and carotenoids), and efficiency of the photosystem II (PSII in terms of F/F and performance index), thus improving faba bean growth, green pod yield, and water use efficiency. Drought stress caused an abnormal state of nutrients and photosynthetic machinery due to increased indicators of oxidative stress (malondialdehyde (MDA), hydrogen peroxide (HO) and superoxide (O)), associated with increased osmoprotectants (proline, glycine betaine, soluble sugars, and soluble protein), non-enzymatic antioxidants (ascorbic acid, glutathione, and α-tocopherol), and enzymatic antioxidant activities (superoxide dismutase, catalase, glutathione reductase, and ascorbate peroxidase). However, foliar-applied GA or Db-H mediated further increases in osmoprotectants, antioxidant capacity, GA, indole-3-acetic acid, and cytokinins, along with decreased levels of MDA and abscisic acid. These results suggest the use of GA or Db-H at the tested concentrations to mitigate drought-induced damage in bean plants to obtain satisfactory growth and productivity under a water deficit of up to 40%.
使用赤霉素（GA）等生长调节剂以及包括稀释蜂蜜（Db - H）在内的生物刺激素，可以提高包括蚕豆（Vicia faba L.）在内的许多作物的耐旱性。Db - H含有高含量的渗透保护剂、矿质营养元素、维生素和多种抗氧化剂，使其成为一种对抗环境胁迫影响的有效生长调节剂。因此，本研究旨在通过叶面喷施GA（20 mg/L）或Db - H（20 g/L），研究在充分浇水（作物蒸散量（ETc）的100%）和干旱胁迫（ETc的60%）条件下蚕豆植株性能（生长和生产力）的潜在改善情况。评估了这些生长调节剂对生长、生产力、生理生化特性、养分状况、抗氧化防御系统和植物激素的改善作用。GA或Db - H减轻了干旱胁迫对细胞膜稳定性、离子渗漏、相对含水量、养分状况、与光合作用相关的叶片色素（叶绿素和类胡萝卜素）以及光系统II效率（以Fv/Fm和性能指数表示的PSII）的负面影响，从而提高了蚕豆的生长、绿荚产量和水分利用效率。干旱胁迫由于氧化应激指标（丙二醛（MDA）、过氧化氢（H₂O₂）和超氧阴离子（O₂⁻））增加，导致养分和光合机制出现异常状态，同时渗透保护剂（脯氨酸、甘氨酸甜菜碱、可溶性糖和可溶性蛋白）、非酶抗氧化剂（抗坏血酸、谷胱甘肽和α - 生育酚）以及酶促抗氧化活性（超氧化物歧化酶、过氧化氢酶、谷胱甘肽还原酶和抗坏血酸过氧化物酶）增加。然而，叶面喷施GA或Db - H进一步介导了渗透保护剂、抗氧化能力、GA、吲哚 - 3 - 乙酸和细胞分裂素的增加，同时降低了MDA和脱落酸的水平。这些结果表明，在测试浓度下使用GA或Db - H可减轻干旱对豆类植物造成的损害，以便在高达40%的水分亏缺条件下获得令人满意的生长和生产力。
