Centro de Citricultura y Producción Vegetal, Departamento de Horticultura, Instituto Valenciano de Investigaciones Agrarias, CV-315, Km 10,700 Moncada, Valencia, Spain.
Departamento de Producción Vegetal, Universitat Politècnica de València, Valencia, Spain.
BMC Plant Biol. 2021 Apr 8;21(1):169. doi: 10.1186/s12870-021-02938-2.
Pepper is one of the most cultivated crops worldwide, but is sensitive to salinity. This sensitivity is dependent on varieties and our knowledge about how they can face such stress is limited, mainly according to a molecular point of view. This is the main reason why we decided to develop this transcriptomic analysis. Tolerant and sensitive accessions, respectively called A25 and A6, were grown for 14 days under control conditions and irrigated with 70 mM of NaCl. Biomass, different physiological parameters and differentially expressed genes were analysed to give response to differential salinity mechanisms between both accessions.
The genetic changes found between the accessions under both control and stress conditions could explain the physiological behaviour in A25 by the decrease of osmotic potential that could be due mainly to an increase in potassium and proline accumulation, improved growth (e.g. expansins), more efficient starch accumulation (e.g. BAM1), ion homeostasis (e.g. CBL9, HAI3, BASS1), photosynthetic protection (e.g. FIB1A, TIL, JAR1) and antioxidant activity (e.g. PSDS3, SnRK2.10). In addition, misregulation of ABA signalling (e.g. HAB1, ERD4, HAI3) and other stress signalling genes (e.g. JAR1) would appear crucial to explain the different sensitivity to NaCl in both accessions.
After analysing the physiological behaviour and transcriptomic results, we have concluded that A25 accession utilizes different strategies to cope better salt stress, being ABA-signalling a pivotal point of regulation. However, other strategies, such as the decrease in osmotic potential to preserve water status in leaves seem to be important to explain the defence response to salinity in pepper A25 plants.
辣椒是全球种植最广泛的作物之一，但对盐度敏感。这种敏感性取决于品种，而我们对它们如何应对这种压力的了解是有限的，主要是从分子角度来看。这就是我们决定进行这项转录组分析的主要原因。分别称为 A25 和 A6 的耐盐和敏感品种在对照条件下生长 14 天，并分别用 70mM 的 NaCl 灌溉。分析生物量、不同生理参数和差异表达基因，以了解两个品种对差异盐度的反应机制。
在对照和胁迫条件下，品种之间发现的遗传变化可以通过降低渗透势来解释 A25 的生理行为，这主要可能是由于钾和脯氨酸积累增加、生长改善（例如扩展蛋白）、更有效的淀粉积累（例如 BAM1）、离子稳态（例如 CBL9、HAI3、BASS1）、光合作用保护（例如 FIB1A、TIL、JAR1）和抗氧化活性（例如 PSDS3、SnRK2.10）。此外，ABA 信号转导（例如 HAB1、ERD4、HAI3）和其他应激信号转导基因（例如 JAR1）的失调似乎对解释两个品种对 NaCl 的不同敏感性至关重要。
在分析生理行为和转录组结果后，我们得出结论，A25 品种利用不同的策略更好地应对盐胁迫，ABA 信号转导是调控的关键。然而，其他策略，如降低渗透势以保持叶片的水分状态，似乎对于解释辣椒 A25 植物对盐度的防御反应很重要。
