Arbuscular mycorrhizae status of host plant affects offspring’s phenotype and transcriptome expression in a low-phosphorus environment

低磷环境下宿主植物的丛枝菌根状态影响其后代的表型和转录组表达

Although the effects of arbuscular mycorrhizal fungi(AMF)on host plants have been well documented,whether the effects of AMF on parental generations affect offspring performance is not fully clear.We conducted a common garden experiment to determine whether AMF status of host plants(Medicago truncatula)affects phenotype and transcriptome expression of their offspring.Seeds from four type parental treatments(low-phosphorus(P)soil without AMF,low-P soil with AMF,high-P soil without AMF and high-P soil with AMF)were grown under low-P(LPS)and normal-P soil(OHS)conditions.The fowering pattern of LP offspring was similar to their parents,such that plants with AMF fowered earlier than those without AMF under OHS condition but were opposite under LPS condition.The transcriptome differential analysis showed that some differential transcripts(45 for parental plants growing under low-P condition and 3 for parental plants growing under high-P condition)expression patterns between offspring were comparable,and that only affected by parental AMF status regardless of the P environment that offspring was grown.Others(146 for parental plants growing under low-P condition and 2 for parental plants growing under high-P condition),however,were affected both by the parental AMF status and the offspring P environment.In addition,the number of differential transcripts between offspring whose parental plants grew under high-P condition was far less than under low-P condition.These results indicate that AMF may not only affect the current generation of host plants but also affect the offspring especially when their parents have experienced a stressful environment.

丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)对于宿主植物的影响已有较多研究,但AMF对于亲代植物的效应能否影响后代表现的问题仍不明晰。我们设计了一个同质园实验来探究亲代宿主植物蒺藜苜蓿(Medicagotruncatula)的AMF状态是否影响其后代的表型和转录组表达。来源于4种亲本处理(低磷不接种AMF,低磷接种AMF,高磷不接种AMF和高磷接种AMF)的种子分别种植于低磷土壤(LPS)以及正常磷土壤(OHS)。结果表明,低磷后代的开花模式与它们的亲代类似,即OHS环境下接种AMF的植株开花时间要早于不接种AMF的植株,但是在LPS环境下情况相反。转录组差异分析结果显示,一部分差异转录本(包括45个低磷亲本处理中表达的差异转录本和3个高磷亲本处理中表达的差异转录本)在后代间的表达模式相似,即仅受亲代AMF状态影响而不受后代生长环境磷水平影响。其余差异转录本(包括146个低磷亲本处理中表达的差异转录本和2个高磷亲本处理中表达的差异转录本),受亲代AMF状态和后代生长环境磷水平的共同影响。同时,高磷亲本处理的后代差异转录本的数目远少于低磷亲本处理。以上结果表明,AMF可能不仅影响宿主植物当代的表现,还可能影响它们的后代,尤其是在亲代经历胁迫环境的情况下。