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

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 (Pn) was observed. This decrease was accompanied with decreases in stomatal conductance (gs), intercellular CO2 concentration (Ci), and transpiration (Tr). 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 (Fv/Fm) 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. Pn was positively correlated with Tr and gs on the 7th day of the treatment. Moreover, Tr was much more sensitive to yeast than was Pn. In general, the foliar application of yeast resulted in decreased Tr 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.

Biochar-biofertilizer combinations enhance growth and nutrient uptake in silver maple grown in an urban soil

“…While no prior published reports on the effects of IY on photosynthetic activity or leaf pigments could be found, foliar application of live S . cerevisiae significantly improved WUE in fava beans [ 100 ] and increased photosynthetic activity in strawberries [ 101 ], and soil inoculation with various live yeasts was shown to increase leaf chlorophyll in sugar beets [ 102 ].…”

“…All treatment combinations in week 10 of the experiment (just before the pest outbreak), showed significantly greater chlorophyll content in leaves with biochar and biofertilizer combinations (S2 Fig in S1 File), and photosynthesis and WUE increased in treatments with biofertilizers (S3 Fig in S1 File). While no prior published reports on the effects of IY on photosynthetic activity or leaf pigments could be found, foliar application of live S. cerevisiae significantly improved WUE in fava beans [100] and increased photosynthetic activity in strawberries [101], and soil inoculation with various live yeasts was shown to increase leaf chlorophyll in sugar beets [102].…”