Partial repair of salinity-induced damage to sprouting sugarcane buds by proline and glycinebetaine pretreatment

Abstract

Sugarcane shows reduced crop stand under relatively suboptimal conditions; the main reason for this is its sensitivity to ionic stress in the soil solution. This research was performed to explore some physiological and developmental changes in the immature sugarcane buds submitted to salt stress and possible role of glycinebetaine (GB) and proline (Pro) in mitigating the ion toxicity in a time course manner. Salinity stress reduced fresh and dry weight, induced the generation of hydrogen peroxide, increased tissue levels of Na(+) sand Cl(-), reduced K(+) and Ca(2+), and K(+):Na(+) and Ca(2+):Na(+) ratios, while increasing the osmolyte synthesis in expanding sugarcane buds. Salinity stress reduced and delayed the formation of new bud leaves and their expansion, which was mainly because of reduction in the number and area of mesophyll cells and poor development of vascular bundles. The pretreatment of bud chips with 20 mM each of GB and Pro decreased tissue levels of Na(+) and Cl(-), reduced the generation of H2O2, improved K(+) and Ca(2+), K(+):Na(+) and Ca(2+):Na(+) ratios, and further increased the levels of GB, free proline (FP), and soluble sugars in the buds. The pretreatment increased mesophyll cell number and expansion of bud leaves and formation of elaborated vascular tissues, which apparently enabled the sprouting buds to adapt to salinity stress. Of the two osmolytes, GB was a relatively better inducer of salinity tolerance than Pro. In short, salinity-induced oxidative stress was the main cause for altered tissue development, the production of which was offset by pretreatment of bud tissues with Pro and GB.

Beneficial role of acetylcholine in chlorophyll metabolism and photosynthetic gas exchange in Nicotiana benthamiana seedlings under salinity stress

“…Ion toxicity is known to disturb physiological and metabolic processes in plants (Rasheed et al . ). The accumulation of Na + in cells and tissues of a plant adversely affects growth and development (Assaha et al .…”

Differential growth and yield responses of salt-tolerant and susceptible rice cultivars to individual (Na+ and Cl−) and additive stress effects of NaCl

“…High concentration of soluble salts in agricultural soils, termed as soil salinity, is a key abiotic stress causing substantial crop yield losses worldwide (Rasheed et al 2015). Therefore, developing salinity-tolerant crop plants holds great significance in meeting the ever-increasing food and feed requirements.…”

Varied Patterns of Sprouting and Nutrient Status of Sugarcane Sprouts in Simulated and Natural Saline/Sodic Soils Across two Growing Seasons

“…Rasheed et al (2016) attributed the reduced and delayed sprouting of sugarcane buds to the enhanced accumulation of toxic ions and production of hydrogen peroxide, a reactive oxygen species (Wahid et al, 2014). We noted that subjecting the sugarcane nodal growing tissues to the salinity/sodicity conditions was more toxic to the shoot bud expansion and production of roots from root primordia most likely due to dual stress of the applied treatments.…”

“…Until recently it is known that the partitioning of essential nutrients to the sprouting buds is a determining factor in salinity tolerance of sugarcane (Wahid et al, 2009). This is particularly important in view of the fact that transition from immature to mature buds and eventually production of sprouts are closely related (Rasheed et al, 2016).…”