TY - JOUR

T1 - Effects of elevated atmospheric CO2 on leaf gas exchange response to progressive drought in barley and tomato plants with different endogenous ABA levels

AU - Wei, Zhenhua

AU - Fang, Liang

AU - Li, Xiangnan

AU - Liu, Jie

AU - Liu, Fulai

PY - 2020

Y1 - 2020

N2 - Background and aims: ABA plays an important role in modulating stomatal response to drought and elevated atmospheric CO2 (e [CO2]). This study aimed to investigate the effect of e[CO2] on the response of leaf gas exchange and plant water relations of barley and tomato plants with different endogenous ABA levels to progressive soil drying. Methods: Barley and tomato plants were grown in ambient (a[CO2], 400 ppm) and e[CO2] (800 ppm) and subjected to progressive drought stress. Wild type (WT) genotypes (Steptoe barley and AC tomato) and their ABA-deficient mutants (Az34 barley and flacca) were examined. Results: e[CO2] sensitized the photosynthetic decline with soil drying. Soil-drying induced stomatal closure was affected by [CO2] in WT genotypes, where e[CO2] sensitized stomatal closure in barley but retarded it in tomato, whereas such effects were absent in mutants. Compared to a[CO2], e[CO2] maintained leaf water potential and improved turgor pressure except in the flacca mutant. For the WT genotypes, the stomata became less sensitive to an increase in leaf ABA concentration ([ABA]leaf) under e[CO2] than a[CO2]; while for both mutants, the stomata was predominately controlled by leaf turgor and not an increase in [ABA]leaf during soil drying. Conclusion: Endogenous ABA level played an important role in modulating the effect of e[CO2] on stomatal response to soil drying. These findings improve our understanding of the mechanisms of stomatal control in monocot and dicot species responding to a future drier and CO2-enriched environment.

AB - Background and aims: ABA plays an important role in modulating stomatal response to drought and elevated atmospheric CO2 (e [CO2]). This study aimed to investigate the effect of e[CO2] on the response of leaf gas exchange and plant water relations of barley and tomato plants with different endogenous ABA levels to progressive soil drying. Methods: Barley and tomato plants were grown in ambient (a[CO2], 400 ppm) and e[CO2] (800 ppm) and subjected to progressive drought stress. Wild type (WT) genotypes (Steptoe barley and AC tomato) and their ABA-deficient mutants (Az34 barley and flacca) were examined. Results: e[CO2] sensitized the photosynthetic decline with soil drying. Soil-drying induced stomatal closure was affected by [CO2] in WT genotypes, where e[CO2] sensitized stomatal closure in barley but retarded it in tomato, whereas such effects were absent in mutants. Compared to a[CO2], e[CO2] maintained leaf water potential and improved turgor pressure except in the flacca mutant. For the WT genotypes, the stomata became less sensitive to an increase in leaf ABA concentration ([ABA]leaf) under e[CO2] than a[CO2]; while for both mutants, the stomata was predominately controlled by leaf turgor and not an increase in [ABA]leaf during soil drying. Conclusion: Endogenous ABA level played an important role in modulating the effect of e[CO2] on stomatal response to soil drying. These findings improve our understanding of the mechanisms of stomatal control in monocot and dicot species responding to a future drier and CO2-enriched environment.

KW - ABA

KW - Barley

KW - CO

KW - Drought

KW - Stomata

KW - Tomato

U2 - 10.1007/s11104-019-04393-3

DO - 10.1007/s11104-019-04393-3

M3 - Journal article

AN - SCOPUS:85076877596

VL - 447

SP - 431

EP - 446

JO - Plant and Soil

JF - Plant and Soil

SN - 0032-079X

ER -