Influences of Saccharomyces cerevisiae on gas exchange and water-use efficiency in Vicia faba L.

Jing Gao; Nan Wang; Gang Zhang; Yonggang Yan; Genxuan Wang; Suiqi Zhang

doi:10.9755/ejfa.2019.v31.i12.2041

Authors

Jing Gao College of Pharmacy and Shaanxi Qinling Application Development and Engineering Center of Chinese Herbal Medicine, Shaanxi University of Chinese Medicine, Xianyang 712046, China
Nan Wang Shaanxi Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Shaanxi University of Chinese Medicine, Xianyang 712083, China
Gang Zhang College of Pharmacy and Shaanxi Qinling Application Development and Engineering Center of Chinese Herbal Medicine, Shaanxi University of Chinese Medicine, Xianyang 712046, China
Yonggang Yan College of Pharmacy and Shaanxi Qinling Application Development and Engineering Center of Chinese Herbal Medicine, Shaanxi University of Chinese Medicine, Xianyang 712046, China
Genxuan Wang College of Life Sciences, Zhejiang University, Hangzhou 310058, China
Suiqi Zhang Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China

DOI:

https://doi.org/10.9755/ejfa.2019.v31.i12.2041

Abstract

To examine the hypothesis that microbes can function as antitranspirants regulating stomatal behavior, we studied the effect of Saccharomyces cerevisiae strain BY4741 on gas exchange and water-use efficiency (WUE) in Vicia faba L. Stomatal aperture and photosynthetic parameters were analyzed every day for 7 days after treatment. In the present study, spraying yeast decreased the stomatal aperture. On the 4th, 5th, 6th, and 7th days after the foliar application of yeast, a decreased in net photosynthetic rate (P_n) was observed. This decrease was accompanied with decreases in stomatal conductance (g_s), intercellular CO₂ concentration (C_i), and transpiration (T_r). The carboxylation efficiency (CE) was reduced by yeast on the 1st day after treatment. On the 1st, 2nd, and 3rd days of treatment, the yeast dramatically decreased the maximum photochemical efficiency of photosystem (PS) II (F_v/F_m) and increased non-photochemical quenching (NPQ); however, these parameters eventually recovered to their normal levels. The marked decrease of qP was observed on the 1st and 2nd days after yeast treatment. At the beginning of the treatment, the yeast decreased electron the transport rate (ETR), but later increased it. Both concentrations of yeast (1×10⁶ and 1×10¹⁰ CFU mL⁻¹) increased the WUE on the 4th, 5th, 6th, and 7th days of treatments. At the concentrations of 1×10⁶ CFU mL⁻¹, yeast acted as a more effective antitranspirant, showing higher WUE, than at the concentration of 1 × 10¹⁰ CFU mL⁻¹. P_n was positively correlated with T_r and g_son the 7th day of the treatment. Moreover, T_r was much more sensitive to yeast than was P_n. In general, the foliar application of yeast resulted in decreased T_r and increased WUE. The yeast-induced decrease in photosynthesis is mainly caused by stomatal closure, suggesting that yeast can be used as an antitranspirant or a priming agent for improving drought tolerance in plants.