低温吸胀对大豆与豌豆种子呼吸代谢的影响

EFFECT OF IMBIBITION UNDER LOW TEMPERATURE ON RESPIRATORY METABOLISM OF PEA AND SOYBEAN SEEDS

本工作研究了5℃低温吸胀对大豆和豌豆整粒种子或种子碎粒呼吸代谢的影响。结果表明:①在5℃吸胀0～1 5min,大豆种子碎粒 EMP 途径和 TCA 循环对总呼吸的相对贡献先增加后降低,并低于对照,豌豆种子碎粒 EMP 途径和 TCA 循环占总呼吸的比例均较高。②与整粒种子先在25℃再转入5℃吸胀的处理相比,若种子先在5℃再转入25℃吸胀(5～25处理),两类种子去子叶胚通过细胞色素途径的呼吸明显降低。③整粒种子经5℃吸胀后转入25℃萌发96～144h,细胞色素氧化酶和琥珀酸脱氢酶活性均显著低于对照(25℃吸胀)。据此队为,呼吸代谢平衡失调是低温吸胀造成种子吸胀冷害的重要原因之一。

The relative contribution of EMP and TCA pathways to total respiration rates in- creased gradually in ground pea seed but increased at first and then decreased rapidly in ground soybean seed when they were kept at 5℃ to imbibe for 0-15min.Respiration rates of cytochrome oxidase pathways in intact soybean and pea seeds imbibed at 5℃ first and then at 25℃(5-25)decreased apparently,compared with the converse treatment(25-5).Ac- tivities of cytochrome oxidase and succinic dehydrogenase were significant lower in seeds germinated at 25℃ for 96-144h after imbibing at 5℃ for 3h than those in control(imbibing at 25℃).It is suggested that damages of the reconstructive processes of the membrane struc- tures and functions in seed cells during low temperature imbibition may be an important cause of respiratory metabolic disorder.