Metabolic responses of alfalfa ( Medicago Sativa L.) leaves to low and high temperature induced stresses

• DOI: 10.5897/ajb10.1433
• Publication Date: 2011-02-14
• Authors: Yiwei Mo; Guobin Liang; Wei-qi Shi; Jianghui Xie
• Keywords: Sucrose-phosphate synthase; Malondialdehyde; Starch synthase

To explore adaptation mechanism of alfalfa to cold and heat stresses, status sucrose metabolism relative water content (RWC) in leaves under low high temperature treatments were studied. Seedlings (35 day old) transferred chambers for treatments. First group was subjected 5°C as (LT) stress, second at 33°C (HT) stress third 25°C the control (CK). Results indicated that, both stresses led an increase degree duration genes expression corresponding enzymes activities phosphate synthase (SPS) (SS), but LT showed a more significant effect. As result, lower starch higher contents soluble reducing sugar, fructose observed stress. Moreover, lowered malondialdehyde (MDA) electrolyte leakage leaves, thus achieving RWC. It suggested relatively RWC by resulted from potential, transpiration can explain reason that plants are cold-tolerant heat-sensitive. Key words : Alfalfa, sucrose, (SPS), content.