Foliar-applied glycine betaine minimizes drought stress-related impact to gas exchange and the photochemical efficiency of PSII in sugarcane

Abstract

Sugarcane is one of the most important crops in the world, but subject to yield losses caused by sporadic droughts during the growing season. To mitigate the effects of drought stress, different strategies have already been used, including the foliar application of glycine betaine (GB). Thus, the present study aimed to evaluate the effect of GB spraying via leaf on gas exchange, chlorophyll fluorescence and on the sugarcane water status subjected to drought stress and rewatering. The experiment was carried out in a greenhouse, using the RB92579 sugarcane variety. A randomized block design was used, in a 3 9 2 factorial scheme, composed of three GB applications (G0-without GB, G1-one application and G2-two applications) and two water treatments: irrigated (Control) and non-irrigated (Drought Stress), with subsequent rewatering. The foliar application of GB minimized the impact of drought stress on gas exchange, on the photochemical efficiency of photosystem II (PSII) and leaf tissue water status in stressed plants. In addition, it favored the energy use in the PSII and reduced photoinhibition, a fact not observed in the G0 stressed plants. Thus, it can be inferred that the GB foliar application mitigates the negative effects of drought stress on gas exchange and photochemical apparatus of PSII in young sugarcane plants.

Induction of regulatory mechanisms by plant growth promoting rhizobacteria in crops facing drought stress

“…2020). Exogenous application of glycine betaine improves the rate of photosynthesis and induces drought tolerance in Saccharum officinarum (de Oliveira Maia Júnior et al . 2020).…”

Applying Biostimulants to Combat Water Deficit in Crop Plants: Research and Debate

“…It is normally used to increase tolerance against abiotic stresses, such as freezing, salinity and drought stress [18]. Foliar application of GB results in rapid uptake, translocating to different plant organs [18], enhancing antioxidant defence [19,20], leaf gas-exchange attributes [21,22] and growth under stress conditions [22]. A recent publication shows how a foliar application of 11.5 g L −1 can increase yield [23].…”