Abstract
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 higher due to the eCO2 supply to acclimate the basil under the DS condition. This study suggests that the combination of eCO2 during DS positively impacts basil’s photosynthetic parameters and biochemical traits than aCO2.
Highlights
Over the last few decades, the influence of global climate change on agricultural productivity has emerged as a critical research issue [1]
nitrogen balance index (NBI) increased under drought stress (DS) + aCO2 by 26.2% compared to control
LChl increased by 20% and 16% under DS + aCO2 and DS + elevated CO2 (eCO2), respectively, compared to control (Table 1)
Summary
Over the last few decades, the influence of global climate change on agricultural productivity has emerged as a critical research issue [1]. DS increased the formation of reactive oxygen species (ROS), which includes superoxide and hydrogen peroxide (H2O2) [11,13,14] These ROS are combatted by the plant antioxidant system (ascorbate, glutathione, and superoxide dismutase (SOD)) [13,14]. The expected rise in drought conditions resulting from increased CO2 and temperature in the atmosphere will affect crop growth and production of basil (Ocimum basilicum, L.) [17]. Basil is the most widespread warm-season aromatic and medicinal herb, and it belongs to the subfamily Nepetoidae under the Lamiaceae family [18,19] It is used as an ingredient for commercial fragrances and improves the shelf life of food products [20,21]. The current study’s primary purpose is to understand the effect of DS coupled with eCO2 on several physiological parameters, photosynthetic rates, carotenoids, chlorophylls, and several antioxidant concentrations in basil
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call