种子引发对甜高粱角质层蜡质及其抗性的影响

种子引发是一种可有效提高植物抗性及产量的方法，但引发是否可以调节作物生长期角质层蜡质沉积，从而参与植物抗性，目前尚不清楚。以甜高粱为试验对象，其种子用15% 聚乙二醇（PEG）、150 mg·L^-1水杨酸（SA）、20 mg·L^-1 脱落酸（ABA）、5 mg·L^-1 赤霉素（GA）或水进行引发处理，之后在田间种植（2020年），分析测定了不同生长阶段（苗期、拔节期、抽穗期、成熟期）叶片角质层蜡质含量、叶片失水率、叶绿素浸提率；收获的种子进行第二年种植（2021年），分析种子引发对植株叶片角质层蜡质的跨代效应。结果表明，PEG、SA和ABA引发分别显著增加苗期蜡质总量57.6%，50.8%和80.3%。引发也可增加不同生育期蜡质烷烃组分的含量，其中，ABA引发效果显著，分别显著增加苗期、抽穗期与成熟期烷烃含量58.7%、35.5%和36.5%。具有不同碳链长度的蜡质组分丰度同样受引发影响，特别是C₂₇、C₂₉、C₃₃烷，C₂₈~C₃₂醛与C₂₈醇相对丰度。与此同时，引发后高粱叶片相对含水量增加，叶片失水率、叶绿素浸提率均下降。综合分析认为，PEG、SA和ABA引发均可起到调节作物角质层蜡质沉积、提高角质层抗性的作用。此外，种子引发对蜡质合成的影响具有跨代“记忆”，可为生产中培育抗性品种提供新方法。

Effects of seed priming on cuticular wax and resistance of sweet sorghum

Seed priming is an efficient method to improve plant tolerance and yield. However， it is still not clear whether the deposition of plant cuticular wax is altered by seed priming thus improving plant resistance to some kinds of stress. In this study conducted in 2020， seeds of sweet sorghum （Sorghum bicolor ‘Dochna’） were primed with 15% polyethylene glycol （PEG）， 150 mg·L^-1 salicylic acid （SA）， 20 mg·L^-1 abscisic acid （ABA）， 5 mg·L^-1 gibberellin （GA） or water （control）， and subsequently sorghum plants at four growth stages （seedling， jointing， heading and maturity） were analyzed for total wax content， leaf water loss rate and chlorophyll extraction rate. The seeds were harvested and reseeded in 2021， and the transgenerational effects of seed priming on cuticular wax were measured. It was found that， compared to the control， the contents of total wax at different growth stages were significantly influenced， with 57.6%， 50.8% and 80.3% increases observed at the seedling stage for PEG-， SA- and ABA-priming. The contents of alkanes were increased by 58.7%， 35.5% and 36.5% （P<0.05 in each case） at seedling， heading， and maturity stages for ABA-priming. Furthermore， the relative abundances of C₂₇， C₂₉， and C₃₃ alkanes， C₂₈-C₃₂ aldehydes， and C₂₈ alcohols， were also improved. Meanwhile， seed priming increased the leaf relative water content but reduced the water loss rate and chlorophyll extraction rate. We concluded that PEG-， SA- and ABA-priming all influenced the deposition of cuticular wax， contributing to an improvement in cuticular resistance. Importantly， the effects of seed priming on wax synthesis had transgenerational “memory”， indicating a potential new method for production of “resistant” seed lines.