São Paulo State University (UNESP). Faculty of Agrarian and Veterinary Sciences. Department of Biology Applied to Agriculture, CEP 14884-900, Jaboticabal, São Paulo, Brazil.
São Paulo State University (UNESP). Faculty of Agrarian and Veterinary Sciences. Department of Agricultural Production Sciences, CEP 14884-900, Jaboticabal, São Paulo, Brazil.
Ecotoxicol Environ Saf. 2020 Sep 15;201:110778. doi: 10.1016/j.ecoenv.2020.110778. Epub 2020 May 29.
Field peas (Pisum sativum L.) are widely cultivated throughout the world as a cool season grain and forage crop. Boron (B) toxicity is caused by high B concentration in the soil or irrigation water, and is particularly problematic in medium or heavier textured soil types with moderate alkalinity and low annual rainfall. Previous studies have indicated that B-toxicity increases oxidative stress in plants, and B-tolerance has been considered an important target in field pea plant breeding programmes. Inducers of tolerance may be a promising alternative for plant breeding. Little research has been conducted on the combined use of silicon (Si) and salicylic acid (SA) to remediate B-toxicity in field peas. The present study revealed the physiological and biochemical plant responses of applying Si + SA under B-toxicity (15 mg B L) on two Brazilian field pea cultivars (Iapar 83 and BRS Forrageira). A semi-hydroponic experiment was conducted using a completely randomized factorial design (2 × 5): with two field pea cultivars and five treatments which were formed by individual and combined applications of Si and SA under B-toxicity plus a control (control, B, B + Si, B + SA, and B + Si + SA). Si (2 mmol L) was applied to plants in two forms (root and leaf), while for SA (36 μmol L) only foliar applications were applied. Our results demonstrated that the combined use of exogenous Si + SA in field peas increased tolerance to B-toxicity through an intensified antioxidant plant defence system, resulting in a better regulation of reactive oxygen species (ROS) production and degradation. It significantly increased total chlorophyll and carotenoids contents, the activities of major antioxidant enzymes, and reduced MDA and HO contents, resulting in increased fresh shoot and total plant dry biomass. The application of Si + SA alleviated the inhibitory effects of boron toxicity in field peas, resulting in greater plant growth by preventing oxidative membrane damage through an increased tolerance to B-excess within the plant tissue. Therefore, the use of Si + SA is an important and sustainable strategy to alleviate B-toxicity in field pea cultivation.
野豌豆（Pisum sativum L.）作为一种凉爽季节的粮食和饲料作物，在世界各地广泛种植。硼（B）毒性是由土壤或灌溉水中的高 B 浓度引起的，在中等或较重质地的土壤类型中，特别是在中等碱性和低年降雨量的土壤中，硼毒性问题尤为突出。先前的研究表明，B 毒性会增加植物的氧化应激，而 B 耐受性被认为是野豌豆植物育种计划的一个重要目标。诱导剂可能是植物育种的一种有前途的替代方法。硅（Si）和水杨酸（SA）联合使用来修复野豌豆 B 毒性的研究较少。本研究揭示了在两种巴西野豌豆品种（Iapar 83 和 BRS Forrageira）中，在 B 毒性（15mgB L）下施用 Si+SA 对植物生理生化的影响。采用完全随机析因设计（2×5）进行半水培实验：两个野豌豆品种和五个处理，每个处理由单独和组合应用 Si 和 SA 在 B 毒性下组成，外加一个对照（对照、B、B+Si、B+SA 和 B+Si+SA）。Si（2mmol L）以两种形式（根和叶）施用给植物，而 SA（36μmol L）仅进行叶面喷施。我们的结果表明，野豌豆中 Si+SA 的联合使用通过强化抗氧化植物防御系统提高了对 B 毒性的耐受性，从而更好地调节活性氧（ROS）的产生和降解。它显著增加了总叶绿素和类胡萝卜素含量、主要抗氧化酶的活性，降低了 MDA 和 HO 的含量，从而增加了新梢和总植物干生物量。Si+SA 的应用缓解了野豌豆中硼毒性的抑制作用，通过增加植物组织对 B 过剩的耐受性，防止氧化膜损伤，从而促进了植物生长。因此，使用 Si+SA 是缓解野豌豆栽培中 B 毒性的重要和可持续策略。
