Giorio Pasquale, Cirillo Valerio, Caramante Martina, Oliva Marco, Guida Gianpiero, Venezia Accursio, Grillo Stefania, Maggio Albino, Albrizio Rossella
National Research Council of Italy, Institute for Mediterranean Agricultural and Forestry Systems (CNR-ISAFOM), Ercolano, 80056 Naples, Italy.
Department of Agricultural Science, University of Napoli Federico II, Portici, 80055 Naples, Italy.
Plants (Basel). 2020 Jun 25;9(6):795. doi: 10.3390/plants9060795.
Salt stress is one of the most impactful abiotic stresses that plants must cope with. Plants' ability to tolerate salt stress relies on multiple mechanisms, which are associated with biomass and yield reductions. Sweet pepper is a salt-sensitive crop that in Mediterranean regions can be exposed to salt build-up in the root zone due to irrigation. Understanding the physiological mechanisms that plants activate to adapt to soil salinization is essential to develop breeding programs and agricultural practices that counteract this phenomenon and ultimately minimize yield reductions. With this aim, the physiological and productive performances of Quadrato D'Asti, a common commercial sweet pepper cultivar in Italy, and Cazzone Giallo, a landrace of the Campania region (Italy), were compared under different salt stress treatments. Quadrato D'Asti had higher tolerance to salt stress when compared to Cazzone Giallo in terms of yield, which was associated with higher leaf biomass vs. fruit ratio in the former. Ion accumulation and profiling between the two genoptypes revealed that Quadrato D'Asti was more efficient at excluding chloride from green tissues, allowing the maintenance of photosystem functionality under stress. In contrast, Cazzone Giallo seemed to compartmentalize most sodium in the stem. While sodium accumulation in the stems has been shown to protect shoots from sodium toxicity, in pepper and/or in the specific experimental conditions imposed, this strategy was less efficient than chloride exclusion for salt stress tolerance.
盐胁迫是植物必须应对的最具影响力的非生物胁迫之一。植物耐受盐胁迫的能力依赖于多种机制，这些机制与生物量和产量降低相关。甜椒是一种对盐敏感的作物，在地中海地区，由于灌溉，其根区可能会出现盐分积累。了解植物激活以适应土壤盐渍化的生理机制对于制定应对这一现象并最终将产量降低降至最低的育种计划和农业实践至关重要。为此，在不同盐胁迫处理下，对意大利常见的商业甜椒品种夸德拉托·达斯蒂（Quadrato D'Asti）和坎帕尼亚地区（意大利）的地方品种卡佐内·贾洛（Cazzone Giallo）的生理和生产性能进行了比较。与卡佐内·贾洛相比，夸德拉托·达斯蒂在产量方面对盐胁迫具有更高的耐受性，这与前者较高的叶生物量与果实比率相关。两种基因型之间的离子积累和分析表明，夸德拉托·达斯蒂在从绿色组织中排除氯离子方面更有效，从而在胁迫下维持光合系统功能。相比之下，卡佐内·贾洛似乎将大部分钠分隔在茎中。虽然茎中钠的积累已被证明可以保护地上部分免受钠毒性的影响，但在甜椒中和/或在所施加的特定实验条件下，这种策略在耐盐胁迫方面不如排除氯离子有效。
