Exogenous glycinebetaine application improves yield under water-limited conditions in hybrid sunflower

Abstract

Limited water availability is a severe threat to the sustainability of crop production. Exogenous application of glycinebetaine (GB) has been found very effective in reducing the adverse affects of water scarcity. This study was conducted to examine the role of exogenous GB application in improving the yield of hybrid sunflower (Helianthus annuus L.) under different irrigation regimes. There were three levels of irrigation: Control (four irrigations), three irrigations (irrigation missing at budding stage) and two irrigations (irrigation missing at budding and grain formation stage) in the experiment. While GB was applied exogenously at 100 mM GB each at budding and grain formation stages, the Control treatment did not receive any GB application. Data regarding yield, yield components and quality parameters showed that water stress reduced the head diameter, number of achene per head, 1000-achene weight and yield. Nonetheless, it was significantly improved by the exogenous GB application. Among the qualitative characteristics, protein contents were significantly increased by water stress at different growth stages but were reduced by exogenous GB application. Whilst oil contents were reduced by drought at different stages, GB application, however, did not ameliorate the negative effect of drought stress on achene oil contents. The effects of water stress and foliar application of GB were more pronounced when applied at vegetative stage than at the reproductive stage. Moreover, exogenous GB application was only advantageous under stress conditions.

Targeting Glycinebetaine for Abiotic Stress Tolerance in Crop Plants: Physiological Mechanism, Molecular Interaction and Signaling

“…Glycinebetaine up-regulates the yield under normal or abiotic stress conditions due to its osmoprotective role on photosynthetic machinery and maintaining the ion homeostasis [160]. Moreover, it improves assimilation of CO2 under drought stress [163] and biosynthesis and transport of hormones, for example, CKs, which have a positive role in the transportation of photoassimilates [165].…”

DROUGHT STRESS: Comparative Time Course Action of the Foliar Applied Glycinebetaine, Salicylic Acid, Nitrous Oxide, Brassinosteroids and Spermine in Improving Drought Resistance of Rice

“…Likewise, several studies indicated improved drought resistance in wheat Usha 2003, Horváth et al 2007), rice (Farooq et al 2009a) and sunflower ) by exogenous salicylic acid (SA) application. Exogenous application of glycinebetaine (GB) improved the resistance against drought stress in tobacco (Ma et al 2007), sunflower (Hussain et al 2008b) and rice (Farooq et al 2008c).…”

Pre-sowing Seed Treatment with Proline Improves some Growth, Biochemical aspects, yield quantity and quantity of two sunflower cultivars grown under seawater salinity stress

“…In the meantime, higher concentrations of proline 7.5 mM (P3) decreased significantly all the yield components of the two cultivars of sunflower plants compared with P0 at S0, S1 and S2 seawater salinity stress. Proline as osmoprotectants promotes plant growth and yield under normal or stress conditions due to its osmoprotective effect on photosynthetic machinery and regulation of ion homeostasis (Raza et al, 2007) as well as improving CO 2 assimilation in plants under stress (Hussain et al, 2008) and because of its role in biosynthesis and transport of hormones like cytokinins that may have a role in the transport of photoassimilates (Taize and Zeiger, 2006). Table 5 clearly show that, S1 & S2 irrigation water decreased significantly oil% and protein% of the yielded seeds of two cultivars Sakha 53 and Giza 102 as compared with S0.…”