Glycinebetaine Improves Chilling Tolerance in Hybrid Maize

Abstract

Plant growth and development is hampered by various environmental stresses including chilling. We investigated the possibility of improving chilling tolerance in hybrid maize by glycinebetaine (GB) seed treatments. Maize hybrid (Hycorn 8288) seeds were soaked in 50, 100 and 150 mg l−1 (p.p.m.) aerated solution of GB for 24 h and were dried back. Treated and untreated seeds were sown at 27 °C (optimal temperature) and at 15 °C (chilling stress) under controlled conditions. Germination and seedling growth was significantly hindered under chilling stress. Moreover, chilling stress significantly reduced the starch metabolism and relative water contents (RWC), and increased the membrane electrolyte leakage. However, activities of antioxidants (catalase, superoxide dismutase and ascorbate peroxidase) were increased under stress conditions. Seed treatments with GB improved the germination rate, root and shoot length, seedling fresh and dry weights, leaf and root scores, RWC, soluble sugars, α‐amylase activity and antioxidants significantly compared with untreated seeds under optimal and stress conditions. Induction of chilling tolerance was attributed to maintenance of high tissue water contents, reduced membrane electrolyte leakage, and higher antioxidant activities and carbohydrate metabolism. Seed treatment with 100 mg l−1 GB was the best treatment for improving the performance of hybrid maize under normal and stress conditions compared with control and other levels used.

Characterization of Rice (Oryza sativa L.) Physiological Responses to a-Tocopherol, Glycine Betaine or Salicylic Acid Application

“…In previous studies, plants treated with GB under optimal conditions showed similar results with respect to rice leaf photosynthetic rates and stomatal conductance (Farooq et al, 2008a). Application of SA did not alter leaf photosynthetic rates in mungbean (Vigna radiate L.) plants with respect to leaf photosynthetic rates.…”

“…Application of SA increases mobilization of reserve food materials to the grain during the grain filling process by increasing the activities of hydrolyzing and oxidative enzymes (Sawhney et al, 1979), hence increasing the number of filled grains. Application of GB increases the synthesis of compatible solutes (Farooq et al, 2008a), whereas application of SA detoxifies superoxide radicals (Bowler et al, 1992), which in turn decreases levels of ROS, thus increasing the integrity of cellular membranes. In addition, GB protects transcriptional and translational machinery, acting as a molecular chaperone in the refolding of enzymes (Rhodes & Hanson, 1993), whereas SA stabilizes trimers of heat shock transcription factors (Larkindale & Knight, 2002), thus rendering protection to membranes and enzymes.…”

“…It enhances tolerance to high temperatures (Paleg et al, 1981), low temperatures (Farooq et al, 2008a), freezing temperatures (WeiBing and Rajashekar, 2001), drought stress (Måkela et al, 2000) and salinity (Harinasut et al, 1996;Rahman et al, 2002). Glycine betaine induces tolerance by protecting the Rubisco enzyme (Paleg et al, 1981) and photosystem II (Allakhverdiev et al, 1996), maintaining turgor pressure (Wyn Jones, 1984) and ion homeostasis, and through alteration of parts of signal transduction (Ashraf & Foolad, 2007).…”

Gas exchange and chlorophyll synthesis of maize cultivars are enhanced by exogenously-applied glycinebetaine under drought conditions

“…Furthermore, some plant species cannot synthesize GB in sufficient amounts, and its exogenous ap-plication becomes indispensable to induce stress tolerance. GB is involved in higher plants as a defensive response to extreme conditions of salt, drought, temperature or light stress (Farooq et al 2008). It stabilizes the structures and activities of enzymes and protein complexes and maintains the integrity of membranes against the damaging effects of abiotic stresses (Sakamoto and Murata 2002).…”

Effects of High Night Temperature on Crop Physiology and Productivity: Plant Growth Regulators Provide a Management Option

“…superoxide dismutase, catalase and enzymes of the ascorbate and glutathione cycle) (Zhang & Kirkham, 1996). Glycine betaine and SA are synthesized in the plants and play important but different, roles in preventing oxidative damage to the membranes (Bowler et al, 1992;Demiral & Turkan, 2004) and inducing theromotolerance in plants subjected to stresses (Ashraf & Foolad, 2007;Caldas et al, 1999;Farooq et al, 2008aFarooq et al, , 2008bLarkindale & Huang, 2004;Mohammed & Tarpley, 2009b;Pan et al, 2006;Raskin, 1992). The commercial availability of GB and SA provides potential crop-management options to reduce crop heat stress events.…”