《植物生理学报》 2017, 53(5): 873-880

干旱胁迫下外源ABA对甘薯苗期叶片光合特性及相关生理指标的影响

孙哲¹, 范维娟³, 刘桂玲¹, 田昌庚¹, 张鹏³, 柳洪鹃², 杨俊⁴, 赵丰玲¹, 史春余^2,*

¹泰安市农业科学研究院, 山东泰安271000; ²山东农业大学农学院, 山东泰安271018; ³中国科学院分子植物科学卓越创新中心/植物生理生态研究所植物分子遗传国家重点实验室, 上海200032; ⁴中国科学院上海辰山植物科学研究中心/上海辰山植物园上海市资源植物功能基因组学重点实验室, 上海201602

通信作者：史春余；E-mail: scyu@sdau.edu.cn

摘　要：

选用食用型甘薯品种‘泰中6号’为材料, 以正常灌水处理为对照, 研究干旱胁迫下外源喷施脱落酸(ABA)对甘薯叶片光合特性及相关生理指标的影响。结果表明: 干旱胁迫使甘薯叶片脯氨酸、过氧化氢(H₂O₂)、丙二醛(MDA)含量增加, 外源ABA处理能减少MDA的积累, 使其含量处于较低水平。外源ABA能够提高叶片净光合速率(P_n), 降低气孔导度(G_s)和蒸腾速率(T_r), 提高水分利用效率(WUE)。ABA处理能防止叶绿素降解并对干旱引起的最大光能转化效率(F_v/F_m)、实际光化学效率(Φ_PSII)、光化学猝灭系数qP下降及非光化学猝灭系数(NPQ)升高有明显的缓解作用。干旱胁迫下, H₂O₂的积累伴随着具有抗氧化作用的SOD和POD酶活性的提高, 而ABA处理能增加H₂O₂的积累, 并进一步提高这些酶的活性。干旱胁迫下, 外施ABA能增强甘薯的抗氧化防护系统, 提高水分利用效率, 提高甘薯的抗旱性。正常灌水条件下外施 ABA对甘薯生长前期叶片生理特性的影响作用不显著。

关键词：甘薯; 干旱胁迫; ABA; 光合特性; 抗氧化酶

收稿：2017-03-08   修定：2017-04-14

资助：国家自然科学基金项目(31371577)、山东省现代农业(薯类)产业技术体系(SDAIT-10-021-18)、山东省农业科学院农业科技创新工程(CXGC2016B04)和泰安市农业良种工程项目(2015LZ06)。

Effects of exogenous ABA on leaf photosynthetic characteristics and associated physiological indexes of sweetpotato (Ipomoea batatas) seedlings under drought stress

SUN Zhe¹, FAN Wei-Juan³, LIU Gui-Ling¹, TIAN Chang-Geng¹, ZHANG Peng³, LIU Hong-Juan², YANG Jun⁴, ZHAO Feng-Ling¹, SHI Chun-Yu^2,*

¹Tai’an Academy of Agricultural Sciences, Tai’an, Shandong 271000, China; ²Agronomy College, Shandong Agricultural University/State Key Laboratory of Crop Biology, Tai’an, Shandong 271018, China; ³National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; ⁴Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Plant Science Research Center, Chinese Academy of Sciences, Shanghai Chenshan Botanical Garden, Shanghai 201602, China

Corresponding author: SHI Chun-Yu; E-mail: scyu@sdau.edu.cn

Abstract:

Using sweetpotato (Ipomoea batatas) cultivar ‘Taizhong 6’ as material and the regular water supply as control, the effects of exogenous ABA on leaf photosynthetic characteristics and associated physiological indexes under drought stress were studied. The results showed that the contents of proline, H₂O₂ and MDA were increased under drought stress. The exogenous ABA treatment alleviated the increase of MDA, improved leaf P_n, decreased G_s and T_r, and increased WUE in sweetpotato plants under drought stress. The ABA application prohibited the degradation of chlorophyll and alleviated the decrease of maximal PSII efficiency (F_v/F_m) and quantum efficiency of PSII (Φ_PSII) and the increase of non-photochemical quenching coefficient (NPQ). Under drought stress, H₂O₂ accumulation was associated with the increasing activities of SOD and POD, and ABA application could increase H₂O₂ accumulation by further improving activities of these enzymes. Our results illustrated that exogenous ABA could enhance antioxidant defense system, increase water use efficiency, and improve drought resistance of sweet potato under drought stress. Nevertheless, under regular water supply conditions, the effect of exogenous ABA on leaf physiological property during earlier growth stage of sweetpotato was not significant.

Key words: sweetpotato (Ipomoea batatas); drought stress; ABA; photosynthetic characteristics; antioxidant enzymes