AUTHOR=Javaid Muhammad Mansoor , Wang Xiukang , Florentine Singarayer K. , Ashraf Muhammad , Mahmood Athar , Li Feng-Min , Fiaz Sajid 

TITLE=Effects on Photosynthetic Response and Biomass Productivity of Acacia longifolia ssp. longifolia Under Elevated CO2 and Water-Limited Regimes

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.817730

DOI=10.3389/fpls.2022.817730

ISSN=1664-462X

ABSTRACT=<p>It is known that the impact of elevated CO<sub>2</sub> (eCO<sub>2</sub>) will cause differential photosynthetic responses in plants, resulting in varying magnitudes of growth and productivity of competing species. Because of the aggressive invasive nature of <italic>Acacia longifolia</italic> ssp. <italic>longifolia</italic>, this study is designed to investigate the effect of eCO<sub>2</sub> on gas exchange parameters, water use efficiency, photosystem II (PSII) activities, and growth of this species. Plants of <italic>A. longifolia</italic> ssp. <italic>longifolia</italic> were grown at 400 ppm (ambient) and 700 ppm (elevated) CO<sub>2</sub> under 100 and 60% field capacity. Leaf gas exchange parameters, water use efficiency, intrinsic water use efficiency, instantaneous carboxylation efficiency, and PSII activity were measured for 10 days at 2-day intervals. eCO<sub>2</sub> mitigated the adverse effects of drought conditions on the aforementioned parameters compared to that grown under ambient CO<sub>2</sub> (aCO<sub>2</sub>) conditions. <italic>A. longifolia</italic>, grown under drought conditions and re-watered at day 8, indicated a partial recovery in most of the parameters measured, suggesting that the recovery of this species under eCO<sub>2</sub> will be higher than that with aCO<sub>2</sub> concentration. This gave an increase in water use efficiency, which is one of the reasons for the observed enhanced growth of <italic>A. longifolia</italic> under drought stress. Thus, eCO<sub>2</sub> will allow to adopt this species in the new environment, even under severe climatic conditions, and foreshadow its likelihood of invasion into new areas.</p>