适宜低温锻炼提高冷敏感植物玉米和番茄的抗冷性及其生理基础  

Increment of Chilling Tolerance and Its Physiological Basis in Chilling-sensitive Corn Sprouts and Tomato Seedlings after Cold-hardening at Optimum Temperatures

作　　者：简令成[1] 卢存福[2] 李积宏[3] LI Paul H 

机构地区：[1]中国科学院植物研究所,北京100093 [2]北京林业大学生物科学与技术学院,北京100083 [3]阿尔伯达大学农业,食物与营养科学系 [4]明尼苏达大学园艺科学系植物抗逆实验室,美国圣保罗mn55108

出　　处：《作物学报》2005年第8期971-976,共6页Acta Agronomica Sinica

基　　金：国家自然科学基金(30271067)资助。~~

摘　　要：研究了冷敏感植物甜玉米和番茄在生长临界温度锻炼下抗冷性的提高以及某些生理指标的适应性变化。结果表明,番茄幼苗经12℃锻炼7d,甜玉米种苗经11℃锻炼8d或15d后,番茄幼苗和甜玉米种苗对2℃低温胁迫的抗性明显提高。经过低温锻炼的番茄幼苗和甜玉米种苗脯氨酸含量较常温下(26℃21℃)生长的显著增加。电镜细胞化学观察结果表明,甜玉米种苗经11℃8d锻炼后,其质膜Ca2+ATPase在2℃冷胁迫后仍保持高活性,甚至有某些提高。而未经锻炼的种苗在同样低温处理后,质膜Ca2+ATPase活性丧失,遭受冷害。本研究结果揭示和证实,喜温植物,无论是单子叶植物玉米,还是双子叶番茄,用其生长临界温度进行低温锻炼是适宜的,能有效地提高冷敏感植物的抗冷能力。Many important cultivated plants, such as tomato, tobacco and maize, have a limited capacity to survive temperatures below freezing, these crops are chilling-sensitive plants which can be killed at temperatures below 10 - 12℃.In contrast, leaves of plants such as cabbage, lettuce, and spinach can develop tolerance to below-freezing temperatures in response to low but above freezing temperatures （2 - 4℃ ）, these plants are chilling-insensitive or chilling-resistant plants.It was considered that chilling-sensitive plants can not increase in freezing or chilling tolerance upon exposure to low nonfreezing temperature, a phenomenon known as cold acclimation. This is because researchers acclimate the chillingsensitive plants at temperatures of 2 - 4℃ which is lethal to these plants. To conform chilling-sensitive plants can also acclimate to low but above freezing temperatures, 10 - 12℃ was selected as the optimum temperatures for cold-hardening in this research. Physiological basis for the requirement and increment of chilling tolerance in chilling-sensitive tomato seedlings and sweet corn sprouts after cold acclimation was elucidated. Results showed that chilling tolerance was increased obviously after cold-hardening at 12℃ for 7 days in tomato seedlings . Sweet corn sprouts acclimated at 11℃ for 8 or 15 days could survive 2℃ 3 d chilling stress（ Fig. 1 and Table 1）. Moreover, spectrophotometric measurement revealed that proline content increased by 48% in tomato seedlings leaves after cold acclimation for 7 days and by 117% in sweet corn sprouts after cold-hardening for 8 days（ Table 2）. Changes of plasma membrane Ca^2＋-ATPase activity, indicated by the status of cerium phosphate precipitated grains, were observed by electronic microscopy in sweet corn seedlings during the course of 2℃ chilling stress. The results showed that many reaction products were distributed on the plasma membrane （PM） ,showing the high activity of Ca^2＋-ATPase, in cells of 11℃, 8 d-hardened sweet corn spr

关 键 词：低温锻炼 番茄 甜玉米 CA^2+-ATPASE 脯氨酸 抗冷性 

分 类 号：S513[农业科学—作物学] S641.2