Department of Agronomy and Zhejiang Key Laboratory of Crop Germplasm, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, China.
Plant Physiology Division, Bangladesh Agricultural Research Institute, Gazipur 1701, Bangladesh.
Cells. 2020 Jun 23;9(6):1530. doi: 10.3390/cells9061530.
Drought and salinity are two of the most frequently co-occurring abiotic stresses. Despite recent advances in the elucidation of the effects of these stresses individually during the vegetative stage of plants, significant gaps exist in our understanding of the combined effects of these two frequently co-occurring stresses. Here, Tibetan wild barley XZ5 (drought tolerant), XZ16 (salt tolerant), and cultivated barley . CM72 (salt tolerant) were subjected to drought (D), salinity (S), or a combination of both treatments (D+S). Protein synthesis is one of the primary activities of the green part of the plant. Therefore, leaf tissue is an important parameter to evaluate drought and salinity stress conditions. Sixty differentially expressed proteins were identified by mass spectrometry (MALDI-TOF/TOF) and classified into 9 biological processes based on Gene Ontology annotation. Among them, 21 proteins were found to be expressed under drought or salinity alone; however, under D+S, 7 proteins, including S-adenosylmethionine synthetase 3 (SAMS3), were exclusively upregulated in drought-tolerant XZ5 but not in CM72. carries both N-terminal and central domains compared with and activates the expression of several ethylene (ET)-responsive transcription factors. is mainly expressed in the roots and stems, and HvSAMS3 is a secretory protein located in the cell membrane and cytoplasm. Barley stripe mosaic virus-based virus-induced gene silencing (BSMV-VIGS) of in XZ5 severely compromised its tolerance to D+S and significantly reduced plant growth and K uptake. The reduced tolerance to the combined stress was associated with the inhibition of polyamines such as spermidine and spermine, polyamine oxidase, ethylene, biotin, and antioxidant enzyme activities. Furthermore, the exogenous application of ethylene and biotin improved the tolerance to D+S in BSMV-VIGS:HvSAMS3-inoculated plants. Our findings highlight the significance of in the tolerance to D+S in XZ5.
干旱和盐度是两种最常同时发生的非生物胁迫。尽管最近在阐明植物营养生长阶段这些胁迫单独作用方面取得了进展，但我们对这两种经常同时发生的胁迫的综合作用仍存在很大的认识差距。在这里，对西藏野生青稞 XZ5（耐旱）、XZ16（耐盐）和栽培青稞 CM72（耐盐）进行了干旱（D）、盐度（S）或两者联合处理（D+S）。蛋白质合成是植物绿色部分的主要活动之一。因此，叶片组织是评估干旱和盐度胁迫条件的一个重要参数。通过质谱（MALDI-TOF/TOF）鉴定了 60 种差异表达蛋白，并根据基因本体注释将其分类为 9 个生物过程。其中，有 21 种蛋白在单独干旱或盐度胁迫下表达；然而，在 D+S 下，只有耐旱性的 XZ5 中上调了 7 种蛋白，包括 S-腺苷甲硫氨酸合成酶 3（SAMS3），而 CM72 中则没有。 与 和 相比，携带 N 端和中央结构域，并激活了几个乙烯（ET）响应转录因子的表达。 主要在根和茎中表达，HvSAMS3 是一种位于细胞膜和细胞质中的分泌蛋白。基于大麦条纹花叶病毒的病毒诱导基因沉默（BSMV-VIGS）对 XZ5 中的 ，严重削弱了其对 D+S 的耐受性，并显著降低了植物的生长和 K 吸收。对联合胁迫的耐受性降低与多胺如亚精胺和精胺、多胺氧化酶、乙烯、生物素和抗氧化酶活性的抑制有关。此外，外源乙烯和生物素的应用提高了 BSMV-VIGS：HvSAMS3 接种植物对 D+S 的耐受性。我们的研究结果强调了 对 XZ5 耐受 D+S 的重要性。
