Center of Molecular Ecophysiology (CMEP), College of Resources and Environment, Southwest University, Chongqing, China.
Physiol Plant. 2022 Jan;174(1):e13641. doi: 10.1111/ppl.13641.
The present study explores the interaction of water supply and rhizobia inoculation on CO and H O gas exchange characteristics, physiological and biochemical traits in seedlings of Robinia pseudoacacia L. originating from two provenances with contrasting climate and soil backgrounds: the Gansu Province (GS) in northwest China and the Dongbei region (DB) of northeast China. Rhizobia strains were isolated from the 50-years old Robinia forest sites grown in the coastal region of east China. Robinia seedlings with and without rhizobia inoculation were exposed to normal water supply, moderate drought, and rewatering treatments, respectively. After 2 weeks of drought treatment, photosynthetic and physiological traits (net photosynthetic rate, stomatal conductance, stable isotope signature of carbon, malondialdehyde and hydrogen peroxide content) of Robinia leaves were significantly altered, but after rewatering, a general recovery was observed. Rhizobia inoculation significantly increased the drought resistance of both Robinia provenances by promoting photosynthesis, increasing the foliar N content and reducing the accumulation of malondialdehyde and hydrogen peroxide. Among the two provenances, DB plants developed more nodules than GS plants, but GS plants were more drought-tolerant than DB plants, both inoculated or noninoculated, indicated by the foliar gas exchange parameters and biochemical traits studied. Our results also show that inoculation of rhizobia could significantly improve the drought resistance of Robinia in both provenances. The present study contributes to the scientific background for the selection of drought-resistant varieties of Robinia to ensure the success of future afforestation projects in degraded terrestrial ecosystems under global climate change.
本研究探讨了供水和根瘤菌接种对来自具有不同气候和土壤背景的两个起源地（中国西北的甘肃省（GS）和中国东北的东北地区（DB））的刺槐幼苗的 CO 和 H O 气体交换特性、生理生化特性的相互作用。从中国东部沿海地区种植了 50 年的刺槐林地点分离出根瘤菌菌株。对有和没有根瘤菌接种的刺槐幼苗分别进行正常供水、中度干旱和再浇水处理。干旱处理 2 周后，刺槐叶片的光合和生理特性（净光合速率、气孔导度、碳稳定同位素特征、丙二醛和过氧化氢含量）发生了显著变化，但再浇水后，普遍得到恢复。根瘤菌接种通过促进光合作用、增加叶片氮含量以及减少丙二醛和过氧化氢的积累，显著提高了两个起源地刺槐的耐旱性。在两个起源地中，DB 植物比 GS 植物形成更多的根瘤，但 GS 植物比 DB 植物更耐旱，无论是接种还是未接种，这可以从研究的叶片气体交换参数和生化特性看出。我们的研究结果还表明，接种根瘤菌可以显著提高两个起源地刺槐的耐旱性。本研究为在全球气候变化下退化陆地生态系统未来造林项目中选择耐旱刺槐品种提供了科学背景。
