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=Volume 13 - 2022

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=It is known that the impact of elevated CO2 (eCO2) 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 A. longifolia subspecies longifolia, this study was designed to investigate the effect of eCO2 on gas exchange parameters, water use efficiency, Photosystem II (PSII) activities, and growth of this species. Plants of A. longifolia subspecies longifolia were grown at 400 ppm (ambient) and 700 ppm (elevated) CO2 under100%  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 two-day intervals. Elevated CO2 mitigated the adverse effects of drought conditions on the afore-mentioned parameters compared to that grown under ambient CO2 conditions. Acacia longifolia, 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 eCO2 will be higher than with ambient CO2 (aCO2) concentration. This gave an increase in water use efficiency which is one reason for the observed enhanced growth of A. longifolia under drought stress. Thus eCO2 will allow to adopt this species in the new environment, even under severe climatic conditions and foreshadow its likelihood of invasion into new areas.