Drought and Elevated CO2 Impacts Photosynthesis and Biochemicals of Basil (Ocimum basilicum L.)

作者：T. Casey Barickman, Bikash Adhikari, Akanksha Sehgal, Charles Hunt Walne, K. Raja Reddy, Wei Gao · 发表于：Stresses · 年份：2021 · DOI：10.3390/stresses1040016 · 被引用次数：25 · 研究领域：Plant responses to elevated CO2、Plant Water Relations and Carbon Dynamics、Plant Parasitism and Resistance

Drought-induced reduction in crop growth and productivity can be compensated by increasing atmospheric carbon dioxide (CO2), a significant contributor to climate change. Drought stress (DS) affects crops worldwide due to dwindling water resources and irregular rainfall patterns. The experiment was set up under a randomized complete block design within a three-by-two factorial arrangement. Six SPAR chambers represent three blocks (10 replications each), where each chamber has 30 pots in three rows. Each chamber was maintained with 30/22 (day/night) °C temperature, with either ambient (aCO2; 420 ppm) or elevated CO2 (eCO2; 720 ppm) concentrations. This experiment was designed to address the impact of DS on the physiological and biochemical attributes and study how the eCO2 helps alleviate the adversity of DS in basil. The study demonstrated that DS + eCO2 application highly accelerated the decrease in all forms of carotene and xanthophylls. eCO2 positively influenced and increased anthocyanin (Antho) and chlorophyll (LChl). eCO2 supplementation increased LChl content in basil under DS. Furthermore, DS significantly impeded the photosynthetic system in plants by decreasing CO2 availability and causing stomatal closure. Although eCO2 did not increase net photosynthesis (Pn) activity, it decreased stomatal conductance (gs) and leaf transpiration rate (E) under DS, showing that eCO2 can improve plant water use efficiency by lowering E and gs. Peroxidase and ascorbate activity were ...