Details

Autor(en) / Beteiligte

• Liang, Kehao
• Peng, Xiaoying
• Liu, Fulai

Titel

Physiological response of Miscanthus genotypes to salinity stress under elevated CO2

Ist Teil von

• Global change biology. Bioenergy, 2022-07, Vol.14 (7), p.858-874

Ort / Verlag

Oxford: John Wiley & Sons, Inc

Erscheinungsjahr

2022

Link zum Volltext

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• 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. For C4 plants Miscanthus, elevated CO2 (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. e[CO2] could improve water potential of plants under both control and saline conditions, but the magnitude of increase was highly genotypic dependent. Salt stress increased the concentration of 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.