Exogenous Glucose and Abscisic Acid Pre-treatment in Indica Rice ( Oryza sativa L. spp. indica ) Responses to Sodium Chloride Salt Stress

摘要

The aim of this research is to investigate on the osmotic adjustment and pigment preservation by soluble sugar accumulation in salt stressed rice using exogenous glucose and abscisic acid (ABA) application, leading to plant growth and development. Soluble sugars including sucrose, glucose and fructose in the salt-stressed root tissues were continuously increased in the conditions of 111-222 mM glucose and 20-60 μ M ABA treatments and then drop in the extreme 333-444 mM glucose and 80 μ M ABA treatments. Osmolarity in the salt-stressed root tissues showed the similar pattern to the sugar responses and was negatively related to soluble sugar concentration (r = 0.91). Chlorophyll a, chlorophyll b and total carotenoid concentrations in the salt-stressed seedlings were significantly maintained by endogenous sugar osmotic adjustment. In addition to, the high osmolarity in salt-stressed seedlings was negatively related to total chlorophyll stabilization (r = 0.83). The total chlorophyll degradation in the salt-stressed leaf tissues was positively correlated with plant growth defined by shoot height (r = 0.81). Root length, root number and root cortex thickness of salt-stressed rice seedlings showed the highest at 222 mM glucose and 60 μ M ABA treatments for 146.1 cm, 17.3 and 1.3 μ m, respectively. An exogenous application of glucose and ABA in this investigation is an alternative way to acclimatize the rice crop before exposed to soil salinity and further applied for rice cultivation in salinity filed trial.