植物生态学报 ›› 2018, Vol. 42 ›› Issue (6): 681-691.doi: 10.17521/cjpe.2018.0017

• 研究论文 • 上一篇    下一篇

‘波叶金桂’对干旱和高温胁迫的生理生态响应

汪俊宇,王小东,马元丹,傅卢成,周欢欢,王彬,张汝民,高岩()   

  1. 浙江农林大学亚热带森林培育国家重点实验室, 浙江临安 311300
  • 收稿日期:2018-01-14 修回日期:2018-05-12 出版日期:2018-06-20 发布日期:2018-06-20
  • 通讯作者: 高岩 E-mail:gaoyan1960@sohu.com
  • 基金资助:
    国家自然科学基金(31470704);国家自然科学基金(31270756)

Physiological and ecological responses to drought and heat stresses in Osmanthus fragrans ‘Boyejingui’

WANG Jun-Yu,WANG Xiao-Dong,MA Yuan-Dan,FU Lu-Cheng,ZHOU Huan-Huan,WANG Bin,ZHANG Ru-Min,GAO Yan()   

  1. The State Key Laboratory of Subtropical Silviculture, Zhejiang Agriculture and Forestry University, Lin’an, Zhejiang 311300, China
  • Received:2018-01-14 Revised:2018-05-12 Online:2018-06-20 Published:2018-06-20
  • Contact: Yan GAO E-mail:gaoyan1960@sohu.com
  • Supported by:
    Supported by the National Natural Science Foundation of China(31470704);Supported by the National Natural Science Foundation of China(31270756)

摘要:

为了探讨植物对干旱、高温及协同胁迫的响应, 该研究以木犀(Osmanthus fragrans) ‘波叶金桂’为材料, 采用盆栽质量控水法模拟干旱胁迫(对照、轻度、中度和重度)和高温胁迫, 利用动态顶空气体循环吸附法和热脱附-气相色谱-质谱(TDS-GC-MS)联用技术对其挥发性有机化合物(VOCs)进行测定; 同时测定其非结构性碳(NSC)含量及次生代谢酶活性。结果表明: 干旱胁迫对‘波叶金桂’叶片NSC组分含量影响不显著; 可溶性糖和淀粉含量在高温胁迫下显著降低, 在协同胁迫后持续性下降, 重度协同胁迫下, 葡萄糖、果糖、蔗糖和淀粉分别比对照降低47.7%、46.4%、34.4%和38.2%。干旱胁迫和协同胁迫下3-羟基-3-甲基戊二酸单酰辅酶A还原酶(HMGR)、1-脱氧木酮糖-5-磷酸还原酶(DXR)活性表现出先上升后下降, 而脂氧合酶(LOX)活性表现出持续性上升趋势; 高温胁迫后, HMGR、DXR和LOX活性显著高于对照。干旱胁迫下萜烯类VOCs释放量表现出先上升后下降趋势, 中度干旱胁迫和高温胁迫下分别比对照高37.9%和32.3%; 协同胁迫下萜烯类释放量逐渐降低, 干旱、高温和协同胁迫诱导醛类释放量明显增加。上述结果表明: 干旱胁迫条件下, ‘波叶金桂’通过NSC进行自我渗透调节, 同时合成大量萜烯类化合物来提高抗旱性; ‘波叶金桂’调控萜烯类化合物合成以及绿叶挥发物(GLVs)的释放抵御高温胁迫; 协同胁迫下萜烯类化合物的合成途径受阻, ‘波叶金桂’提高GLVs合成与释放量抵御协同胁迫; 中度和重度协同胁迫导致‘波叶金桂’细胞膜严重受损, 自我调节能力降低。

关键词: 木犀, 干旱高温胁迫, 非结构性碳, 挥发性有机化合物, 次生代谢酶

Abstract:
Aims Drought and heat stresses are two critical environmental factors affecting the growth and development of plants; climate change has exacerbated the occurrence of these conditions in many parts of the world. To elucidate the mechanisms of responses to drought and heat stresses in Osmanthus fragrans, we studied changes in nonstructural carbohydrate (NSC) and volatile organic compounds (VOCs) emissions using 3-year-old seedlings (cultivar ‘Boyejingui’) under conditions of low drought (LD), moderate drought (MD) and severe drought (SD), interactively with heat treatments (40 °C in daytime (12 h) and 30 °C at night (12 h)).
Methods The VOCs emissions were measured using the dynamic headspace air-circulation method, and the composition and content of VOCs were analyzed using the thermal desorption system/gas chromatography/mass spectrometer technique (TDS-GC-MS). We determined the content of NSC and activities of lipoxygenase (LOX), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) and 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) in seedlings under different drought and heat treatments.
Important findings The content of NSC in leaves was not significantly affected by drought stress. The contents of soluble sugar and starch were significantly reduced by heat stress as well as combination of drought and heat stresses. The combination of severe drought and heat treatment significantly reduced the contents of glucose, fructose, sucrose and starch by 47.7%, 46.4%, 34.4% and 38.2% (p < 0.05), respectively. There were differences among the activities of HMGR, DXR and LOX in response to drought and heat stresses. Under drought and combined stresses, the activities of HMGR and DXR increased first and then decreased, and the LOX activity increased. The activities of HMGR, DXR and LOX were significantly higher under heat stress than in controls. The release of terpenes increased first and then decreased with the level of drought treatments. MD and SD stress stimulated the release of terpenes by 37.9% and 32.3% (p < 0.05), respectively, but the combined stresses induced a reduction in the release of terpenes. The release of aldehydes increased significantly in response to drought, heat treatment, and their combination. The results indicated that ‘Boyejingui’ seedlings can enhance resistance to drought stress by adjusting contents of non-structural carbohydrate and releasing terpene compounds. They also adjusted the biosynthesis of terpene compounds and GLVs emission to resist against heat stress. However, the biosynthesis pathway of terpene compounds was blocked in the occurrence of both drought and heat stresses, when the enhanced release of GLVs facilitated the resistance. Under heat stress, moderate and severe drought caused severe damage to cell membranes, thus reducing the self-regulatory capacity.

Key words: Osmanthus fragrans, drought and heat stress, non-structural carbohydrate, volatile organic compounds, secondary metabolic enzymes