State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China; University of Chinese Academy of Sciences, Beijing, China.
State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China.
Ecotoxicol Environ Saf. 2018 Nov 30;164:344-354. doi: 10.1016/j.ecoenv.2018.08.004. Epub 2018 Aug 18.
Quinoa (Chenopodium quinoa Willd.), a highly nutritious grain crop, is resistant to abiotic stresses (drought, salinity, and cold) and offers an alternate crop to endure harsh environmental conditions under the face of climate change. Naturally, quinoa genome displays a wide degree of variabilities in drought tolerance strategies. Therefore, the present study was designed to investigate drought tolerance variations and stress tolerance enhancement in four quinoa genotypes (Pichaman, Colorado-407D, IESP and 2-Want) thorough foliage-applied HO with the purpose of identifying suitable genotype for water limited environments. The plants were exposed to two watering regimes (75% and 30% pot WHC) and foliage-applied HO treatments (15 mM). The drought stress significantly reduced plant growth, relative water contents, chlorophyll and carotenoids contents and increased ROS production (HO and O) resulting in higher oxidative damage in all quinoa genotypes. Besides, drought stress significantly enhanced the antioxidants (SOD, PPO, and PAL) activity, total soluble sugars, proline, AsA contents and increased the total accumulation of measured inorganic ions in all quinoa genotypes. The PCA analysis indicated that parameters related to osmotic adjustment and antioxidant capacity were more pronounced in 2-Want and IESP genotypes, while parameters depicting oxidative damage were higher in Colorado-407D and more specifically in Pichaman. However, foliage-applied HO effectively improved the osmolytes accumulation, antioxidants activity and K/Na ratio which increased water relations, reduced lipid peroxidation and ultimately resulted in higher plant growth. Overall, 2-Want and IESP genotypes were found relatively more drought resistant, while exogenous application of HO can be opted for more improvement in osmotic adjustment and antioxidant system, which may further enhance drought tolerance, even in sensitive genotypes of quinoa, such as Pichaman.
藜麦（Chenopodium quinoa Willd.）是一种营养丰富的粮食作物，对非生物胁迫（干旱、盐度和寒冷）具有很强的抗性，并提供了一种替代作物，可以在气候变化下恶劣的环境条件下生存。藜麦的基因组自然显示出对干旱耐受策略的广泛多样性。因此，本研究旨在通过叶面喷施 HO 来研究四个藜麦基因型（Pichaman、Colorado-407D、IESP 和 2-Want）的耐旱性变化和胁迫耐受性增强，目的是鉴定适合缺水环境的基因型。将植物暴露于两种浇水制度（75%和 30%的罐 WHC）和叶面喷施 HO 处理（15 mM）下。干旱胁迫显著降低了植物的生长、相对水分含量、叶绿素和类胡萝卜素含量，并增加了 ROS 产生（HO 和 O），导致所有藜麦基因型的氧化损伤增加。此外，干旱胁迫显著增强了抗氧化剂（SOD、PPO 和 PAL）活性、总可溶性糖、脯氨酸、AsA 含量，并增加了所有藜麦基因型中测量的无机离子的总积累。PCA 分析表明，与渗透调节和抗氧化能力相关的参数在 2-Want 和 IESP 基因型中更为显著，而描述氧化损伤的参数在 Colorado-407D 中更高，特别是在 Pichaman 中更高。然而，叶面喷施 HO 有效地提高了渗透物质的积累、抗氧化剂活性和 K/Na 比，从而改善了水分关系，降低了脂质过氧化作用，最终导致植物生长更高。总的来说，2-Want 和 IESP 基因型被发现相对更耐旱，而外源应用 HO 可以更好地改善渗透调节和抗氧化系统，这可以进一步增强耐旱性，即使在藜麦的敏感基因型中，如 Pichaman。
