Bączek-Kwinta Renata
Department of Plant Physiology, Breeding and Seed Science, Faculty of Agriculture and Economics, University of Agriculture in Krakow, Podłużna 3, 30-239 Kraków, Poland.
Plants (Basel). 2022 Jul 4;11(13):1773. doi: 10.3390/plants11131773.
Light increases the germinability of positively photoblastic seeds and inhibits the germination of negative ones. In an area where plant-generated smoke from fire is a periodically occurring environmental factor, smoke chemicals can affect the germination of seeds, including those that are photoblastically sensitive. Moreover, as smoke and its compounds, mostly karrikin 1, KAR1, have been used for priming the seeds of many species, including photoblastic ones, a systematic review of papers dealing with the phenomenon was conducted. The review indicates that the unification of experimental treatments (light spectrum, intensity and photoperiod, and KAR1 concentration within the species) could improve the quality of global research on the impact of smoke chemicals on photoblastic seeds, also at the molecular level. The review also reveals that the physiologically active concentration of KAR1 varies in different species. Moreover, the physiological window of KAR's impact on germination can be narrow due to different depths of primary seed dormancy. Another concern is the mode of action of different smoke sources and formulations (aerosol smoke, smoke-saturated water), or pure smoke chemicals. The reason for this concern is the additive or synergetic effect of KARs, cyanohydrins, nitrates and other compounds, and the presence of a germination inhibitor, trimethylbutenolide (TMB) in smoke and its formulations. Obviously, environmental factors that are characteristic of the local environment need to be considered. From a practical perspective, seeds germinating faster in response to smoke chemicals can outcompete other seeds. Hence, a thorough understanding of this phenomenon can be useful in the restoration of plant habitats and the protection of rare species, as well as yielding an improvement in plants that are sown directly to the field. On the other hand, the application of smoke compounds can induce "suicidal germination" in the photoblastic seeds that are buried in the soil and deplete the soil seed bank of the local population of unwanted species.
光照可提高正光性种子的发芽能力，并抑制负光性种子的萌发。在植物燃烧产生的烟雾作为周期性环境因素的地区，烟雾中的化学物质会影响种子的萌发，包括那些对光敏感的种子。此外，由于烟雾及其化合物（主要是卡里金1，KAR1）已被用于引发许多物种（包括光敏感物种）的种子萌发，因此对涉及该现象的论文进行了系统综述。该综述表明，统一实验处理（光谱、强度和光周期，以及物种内的KAR1浓度）可以提高全球关于烟雾化学物质对光敏感种子影响的研究质量，在分子水平上也是如此。该综述还揭示，KAR1的生理活性浓度在不同物种中有所不同。此外，由于初级种子休眠深度不同，KAR对萌发影响的生理窗口可能很窄。另一个问题是不同烟雾源和配方（气溶胶烟雾、烟雾饱和水）或纯烟雾化学物质的作用方式。产生这一问题的原因是KARs、氰醇、硝酸盐和其他化合物的加性或协同效应，以及烟雾及其配方中存在发芽抑制剂三甲基丁烯内酯（TMB）。显然，需要考虑当地环境特有的环境因素。从实际角度来看，对烟雾化学物质反应更快发芽的种子可以胜过其他种子。因此，深入了解这一现象有助于恢复植物栖息地和保护珍稀物种，也有助于提高直接播种到田间的植物的质量。另一方面，烟雾化合物的应用可能会诱导埋在土壤中的光敏感种子“自杀式萌发”，并耗尽当地不需要物种的土壤种子库。
