昆虫传播的植物病毒往往给作物造成巨大的经济损失,因此选育具有抗病毒的作物品种是目前防治病毒危害的重要手段之一。当前,随着现代化进程的加快,近地面臭氧(O3)浓度不断升高。但这种变化对作物抗性品种的影响如何,目前仍不清楚。
日前,Journal of Experimental Botany 发表了中科院动物所戈峰研究员领导的团队的研究成果。中科院动物研究所种群生态与全球变化研究组模拟研究了近地面臭氧(O3)由目前40ppb浓度增加到未来80ppb情景下,植物对蚜传病毒的作用。研究人员以抗马铃薯Y病毒(PVY)的烟草品种和常规对马铃薯Y病毒(PVY)敏感的烟草品种为研究对象,系统地测定了未来高浓度臭氧(O3)下该2个品种植株的地上生物量、叶绿素、含氮量、非结构性糖、可溶性蛋白、总氨基酸、尼古丁及过氧化物酶活等指标,分析了这2个烟草品种在高浓度臭氧(O3)和病毒(PVY)危害分别和协同作用下的响应机制。
结果发现:在目前臭氧浓度(40ppb)条件下,烟草抗性品种在受到病毒(PVY)侵染后将积累更多的生物量,且碳氮比下降;但在臭氧升高的环境(80ppb)条件下,抗性品种丧失了生物量优势,而保持较低碳氮比。进一步通过比较叶片内过氧化物酶活的变化,发现烟草抗性代价与生物量积累、碳氮比密切相关;当受到高浓度臭氧或植物病毒(PVY)危害等胁迫因子作用时,烟草抗性品种植株内的叶绿素含量稳定,而非抗性品种烟草叶绿素含量下降显著。
该研究表明,抗病毒烟草品种相对于普通品种而言,对高浓度臭氧反映更为敏感;臭氧浓度升高导致烟草对蚜传病毒的抗性下降。(生物谷Bioon.com)
doi:10.1093/jxb/err361
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Enhanced sensitivity to higher ozone in a pathogen-resistant tobacco cultivar
Lefu Ye, Xue Fu, and Feng Ge
Investigations of the effects of elevated ozone (O3) on the virus–plant system were conducted to inform virus pathogen management strategies better. One susceptible cultivar of tobacco (Nicotiana tabacum L. cv. Yongding) and a resistant cultivar (Nicotiana tabacum L. cv. Vam) to Potato virus Y petiole necrosis strain (PVYN) infection were grown in open-top chambers under ambient and elevated O3 concentrations. Above-ground biomass, foliage chlorophyll, nitrogen and total non-structural carbohydrate (TNCs), soluble protein, total amino acid (TAA) and nicotine content, and peroxidase (POD) activity were measured to estimate the effects of elevated O3 on the impact of PVYN in the two cultivars. Results showed that under ambient O3, the resistant cultivar possessed greater biomass and a lower C/N ratio after infection than the susceptible cultivar; however, under elevated O3, the resistant cultivar lost its biomass advantage but maintained a lower C/N ratio. Variation of foliar POD activity could be explained as a resistance cost which was significantly correlated with biomass and C/N ratio of the tobacco cultivar. Chlorophyll content remained steady in the resistant cultivar but decreased significantly in the susceptible cultivar when stressors were applied. Foliar soluble protein and free amino acid content, which were related to resistance cost changes, are also discussed. This study indicated that a virus-resistant tobacco cultivar showed increased sensitivity to elevated O3 compared to a virus-sensitive cultivar..