抗氧化系统参与水杨酸诱导烟草幼苗抗冷性提高的生化机制  

Involvement of Antioxidant System in Salicylic Acid Induced-Chilling Resistance and Biochemical Mechanism in Tobacco(Nicotiana tabacum L.)Seedlings

作　　者：孔春艳 赵静 徐照丽[3] 龚明 KONG Chunyan;ZHAO Jing;XU Zhaoli;GONG Ming(School of Life Sciences,Yunnan Normal University/Engineering Research Center of Sustainable development and Utilization of Biomass Energy of Ministry of Education/Key Laboratory of Biomass Energy and Environmental Biotechnology of Yunnan Province,Kunming,Yunnan 650500,China;Sugarcane Research Institute,Yunnan Academy of Agricultural Sciences,Kaiyuan,Yunnan 661699,China;Yunnan Academy of Tobacco Agricultural Sciences,Kunming,Yunnan 650021,China)

机构地区：[1]云南师范大学生命科学学院/生物能源持续开发利用教育部工程研究中心/云南省生物质能与环境生物技术重点实验室,云南昆明650500 [2]云南省农业科学院甘蔗研究所,云南开远661699 [3]云南省烟草农业科学研究院,云南昆明650021

出　　处：《热带作物学报》2023年第1期154-166,共13页Chinese Journal of Tropical Crops

基　　金：国家自然科学基金项目(No.31860062);中国烟草总公司云南省公司科技计划项目(No.2011YN08,2019530000241012)。

摘　　要：烟草苗期冷害是影响烟草农业生产的一个重要问题,通过各种农艺措施来提高烟苗抗冷性有重要的实际意义。以2个烟草主栽品种‘云烟97’和‘K326’为材料,用浓度为0、0.5、1.0、1.5 mmol/L的水杨酸(SA)对其幼苗进行预处理后进行10℃的低温处理12 d。结果表明,与未处理的对照相比,SA预处理能显著降低‘云烟97’和‘K326’幼苗在低温胁迫过程中叶片的丙二醛(MDA)含量和电解质渗漏率,减缓干物质的消耗速度,增加叶绿素含量和增强根系活力,改善幼苗的根长、表面积、体积和根尖数,促进根系的生长,最终提高烟草幼苗的抗冷性。不同品种有不同的适宜的SA浓度,‘云烟97’的最适浓度为1.5 mmol/L,‘K326’的最适浓度为1.0 mmol/L;SA预处理后,与未预处理的对照相比,在进入低温处理前和低温处理期间,烟草幼苗抗氧化系统中的主要抗氧化剂还原型抗坏血酸(ASA)和谷胱甘肽(GSH)含量均保持在较高的水平,而氧化型ASA和GSH含量则保持在较低水平,还原型抗氧化剂在总抗氧化剂中的比例提高;主要的抗氧化酶抗坏血酸过氧化物酶(APX)、过氧化氢酶(CAT)、愈创木酚过氧化物酶(GPX)、谷胱甘肽还原酶(GR)和超氧化物歧化酶(SOD)均保持较高的活性。这些结果表明,SA预处理后,与未处理对照相比,烟草幼苗均能保持较高的还原型抗氧化剂水平和抗氧化酶活力,并且在低温胁迫期间依然能维持较高的抗氧化能力,这是SA处理能诱导烟草幼苗抗冷性提高的重要生化基础。研究结果不仅对烟草抗冷育苗有参考意义,也对其他农作物、蔬菜的育苗和早期栽培有借鉴作用。Chilling injury during tobacco seedling stage is an important problem affecting tobacco agricultural production,and enhancement of the chilling resistance by various agronomic measures has practical significance.In this study,using two main cultivars Yunyan97 and K326 as the experimental materials,the seedlings were pretreated with salicylic acid(SA)at concentrations 0,0.5,1.0 and 1.5 mmol/L.Then the pretreated seedlings were transferred to 10℃for 12 days for chilling treatment.Compared with the control without SA pretreatment,the SA pretreatment could significantly reduce the malondialdehyde(MDA)content and ratio of electrolyte leakage,slowed down the consumed rate of dry matter,increased chlorophyll content and root vigor,improve root length,surface area,volume and number of roots,promoted the growth of root system under the chilling stress,and finally enhanced the chilling resistance of‘Yunyan 97’and‘K326’seedlings.The optimum SA concentration of different tobacco varieties varied,that for‘Yunyan97’and‘K326’was 1.5 mmol/L and 1.0 mmol/L respectively.After the SA pretreatment,the content of reduced ascorbic acid(ASA)and glutathione(GSH)in the antioxidant defense system in the seedlings remained a higher level,but oxidized ASA and GSH maintained a lower level,and ratio of the reduced antioxidants in total antioxidants increased.Ascorbate peroxidase(APX),catalase(CAT),guaiacol peroxidase(GPX),glutathione reductase(GR)and superoxide dismutase(SOD)maintained high activities compared with the control before and during the chilling treatment.The results indicated that after the SA pretreatment,the seedlings could maintain higher reduced antioxidant level and antioxidant enzyme activity,and remain higher antioxidant capacity,which would lay an important biochemical foundation for SA-induced chilling resistance in tobacco seedlings.The results would not only have reference significance for raising chilling-resistant tobacco seedlings,but also referential value for culture of seedlings and early cultiv

关 键 词：烟草幼苗 水杨酸 低温胁迫 抗冷性 抗氧化系统 

分 类 号：S572[农业科学—烟草工业]