TY - JOUR

T1 - Physiological response of Miscanthus genotypes to salinity stress under elevated CO2

AU - Liang, Kehao

AU - Peng, Xiaoying

AU - Liu, Fulai

N1 - Publisher Copyright: © 2022 The Authors. GCB Bioenergy published by John Wiley & Sons Ltd.

PY - 2022

Y1 - 2022

N2 - Miscanthus is a class of C4 perennial grasses, which can be cultivated on marginal land even with high salinity. However, the future environment may be altered by elevated atmospheric CO2 concentration ([CO2]) and knowledge is limited about the interactive impacts of CO2 enrichment and salinity on this C4 bioenergy crop. In this study, three Miscanthus genotypes (M. sacchariflorus, M. × giganteus, and M. lutarioriparius) were grown under either ambient (400 ppm) [CO2] (a[CO2]) or elevated (800 ppm) [CO2] (e[CO2]) at five salinity levels (0, 50, 100, 150, and 200 mm NaCl denoted as S0, S1, S2, S3, and S4, respectively), and the impacts of e[CO2] on plant physiological responses to salt stress were investigated. Our results suggested that e[CO2] had no obvious effect on net photosynthetic rate (An), but significantly reduced the stomatal conductance (gs), thus improving water use efficiency regardless of salinity levels. In addition, e[CO2] could improve water potential of plants under both control and saline conditions, but the magnitude of increase was highly genotypic dependent. The maximum quantum yield of photosystem II (Fv/Fm) was not altered by e[CO2], which, however, could alleviate the negative effect of salt on Fv/Fm. Furthermore, salt stress increased the concentration of abscisic acid (ABA) in xylem sap and leaves, while the effect of e[CO2] on ABA level was closely associated with genotypes. e[CO2] reduced Na+ concentration and had positive influences on maintaining Na+/K+ ratio, thus favoring ionic homeostasis, although such effect was genotype dependent. Collectively, our data suggested that e[CO2] could partially mitigate the detrimental effects of salinity, conferring higher salt tolerance of Miscanthus.

AB - Miscanthus is a class of C4 perennial grasses, which can be cultivated on marginal land even with high salinity. However, the future environment may be altered by elevated atmospheric CO2 concentration ([CO2]) and knowledge is limited about the interactive impacts of CO2 enrichment and salinity on this C4 bioenergy crop. In this study, three Miscanthus genotypes (M. sacchariflorus, M. × giganteus, and M. lutarioriparius) were grown under either ambient (400 ppm) [CO2] (a[CO2]) or elevated (800 ppm) [CO2] (e[CO2]) at five salinity levels (0, 50, 100, 150, and 200 mm NaCl denoted as S0, S1, S2, S3, and S4, respectively), and the impacts of e[CO2] on plant physiological responses to salt stress were investigated. Our results suggested that e[CO2] had no obvious effect on net photosynthetic rate (An), but significantly reduced the stomatal conductance (gs), thus improving water use efficiency regardless of salinity levels. In addition, e[CO2] could improve water potential of plants under both control and saline conditions, but the magnitude of increase was highly genotypic dependent. The maximum quantum yield of photosystem II (Fv/Fm) was not altered by e[CO2], which, however, could alleviate the negative effect of salt on Fv/Fm. Furthermore, salt stress increased the concentration of abscisic acid (ABA) in xylem sap and leaves, while the effect of e[CO2] on ABA level was closely associated with genotypes. e[CO2] reduced Na+ concentration and had positive influences on maintaining Na+/K+ ratio, thus favoring ionic homeostasis, although such effect was genotype dependent. Collectively, our data suggested that e[CO2] could partially mitigate the detrimental effects of salinity, conferring higher salt tolerance of Miscanthus.

KW - element accumulation

KW - elevated CO

KW - gas exchange

KW - Miscanthus

KW - salinity stress

KW - water relation

U2 - 10.1111/gcbb.12948

DO - 10.1111/gcbb.12948

M3 - Journal article

AN - SCOPUS:85129389712

VL - 14

SP - 858

EP - 874

JO - GCB Bioenergy

JF - GCB Bioenergy

SN - 1757-1693

IS - 7

ER -