Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, Florence, Italy.
National Research Council of Italy, Institute for Sustainable Plant Protection (CNR-IPSP), Torino, Italy.
Physiol Plant. 2021 Dec;173(4):1392-1420. doi: 10.1111/ppl.13425. Epub 2021 May 9.
Soil salinity is among the major abiotic stresses that plants must cope with, mainly in arid and semiarid regions. The tolerance to high salinity is an important agronomic trait to sustain food production. Quinoa is a halophytic annual pseudo-cereal species with high nutritional value that can secrete salt out of young leaves in external non-glandular cells called epidermal bladder cells (EBC). Previous work showed high salt tolerance, but low EBC density was associated with an improved response in the early phases of salinity stress, mediated by tissue-tolerance traits mainly in roots. We compared the transcript profiling of two quinoa genotypes with contrasting salt tolerance patterning to identify the candidate genes involved in the differentially early response among genotypes. The transcriptome profiling, supported by in vitro physiological analyses, provided insights into the early-stage molecular mechanisms, both at the shoot and root level, based on the sensitive/tolerance traits. Results showed the presence of numerous differentially expressed genes among genotypes, tissues, and treatments, with genes involved in hormonal and stress response upregulated mainly in the sensitive genotype, suggesting that tolerance may be correlated to restricted changes in gene expression, at least after a short salt stress. These data, showing constitutive differences between the two genotypes, represent a solid basis for further studies to characterize the salt tolerance traits. Additionally, new information provided by this work might be useful for the development of plant breeding or genome engineering programs in quinoa.
土壤盐度是植物必须应对的主要非生物胁迫之一，主要发生在干旱和半干旱地区。耐盐性是维持粮食生产的重要农艺性状。藜麦是一种盐生一年生假谷物，具有很高的营养价值，它可以通过外部非腺毛细胞（EBC）将盐分从幼叶中分泌出来。以前的工作表明，藜麦具有很高的耐盐性，但低 EBC 密度与在盐胁迫的早期阶段的改善反应有关，这种改善反应是通过组织耐盐性特性介导的，主要在根中。我们比较了两种藜麦基因型的转录组图谱，这些基因型具有不同的耐盐模式，以鉴定参与基因型间早期差异反应的候选基因。转录组图谱分析，得到了体外生理分析的支持，为在地上部和根部水平上的早期阶段分子机制提供了深入的了解，这些机制是基于敏感/耐盐性特征的。结果表明，在不同基因型、组织和处理之间存在大量差异表达的基因，参与激素和应激反应的基因在敏感基因型中上调，这表明耐盐性可能与基因表达的限制变化有关，至少在短期盐胁迫后是这样。这些数据显示了两个基因型之间的组成型差异，为进一步研究耐盐性特征提供了坚实的基础。此外，这项工作提供的新信息可能对藜麦的植物育种或基因组工程计划的发展有用。
