番茄裂果关键基因发掘及ceRNA网络构建

Tomato cracking adversely influences its quality and efficiency. We have previously screened out cracking–resistant genotype and susceptible genotype, and have investigated the physiobiochemic mechanism of tomato cracking from skin physical properties, cell wall composition and the aging of fruit tissue, but the molecular mechanism of tomato cracking is still unclear. It has scientific significance to elucidate the molecular mechanism of cracking. Competing endogenous RNAs (ceRNAs) play important roles in many biological processes, and ceRNA network is a kind of sophisticated transcriptional regulatory network. Based on the previous research, the fruits collected from cracking–resistant genotype and susceptible genotype before and after inducing irrigation will be collected to conduct the transcriptome resequencing. Differently expressed mRNAs will be screened out based on conjoint analysis of multi-transcriptome, and gene identification will then be carried out. Simultaneously, ceRNA (lncRNA、circRNA)–miRNA–mRNA groups will be chosen based on the ceRNA theory. And using RIP technique, we will further identify the interaction between RNAs. Finally, we can define the key genes and ceRNA regulatory network that regulate the tomato cracking. This research can improve the molecular mechanism of tomato cracking and can provide gene resources for tomato cracking–resistant breeding.

番茄裂果问题严重影响其品质和经济效益。项目组前期已筛选出极耐裂果和易裂果的番茄材料，并从果皮物理特性、细胞壁组成、果实组织衰老等方面探讨了番茄裂果的生理机理，但裂果形成的分子机理尚不明确，探明其分子机理有重要的科学意义。竞争性内源RNA（ceRNA）网络是一种精细复杂的转录调控网络，在众多生物学过程中扮演重要角色。本项目拟在前期研究基础上，以耐裂果/易裂果番茄为材料，进行饱和灌溉，诱导裂果，取灌溉前和灌溉后适宜时间点的番茄果实用于转录组测序，进一步采用转录多组学联合分析，筛选差异表达mRNAs并进行功能验证；基于ceRNA理论，候选出调控番茄裂果的ceRNA（lncRNA、circRNA）–miRNA–mRNA组合，利用RIP等技术对RNAs是否存在互作进行验证；最终探明控制番茄裂果的关键基因并建立ceRNA调控网络，研究可丰富番茄裂果形成的分子机理，同时为耐裂果新品种选育提供基因资源

番茄裂果问题严重影响其品质和经济效益。竞争性内源RNA（ceRNA） 网络是一种精细复杂的转录调控网络，在众多生物学过程中扮演重要角色。对于裂果调控网络的研究前期少见报道。本研究以耐裂果/易裂果番茄为材料，进行饱和灌溉，诱导裂果，取灌溉前和灌溉后适宜时间点的番茄果实用于转录组测序，进一步采用转录多组学联合分析，筛选差异表达mRNAs并进行功能验证；基于ceRNA理论，候选出调控番茄裂果的ceRNA，并构建裂果的ceRNA调控网络。研究发现，耐裂果与易裂果番茄的差异mRNA主要聚集在激素、氧化还原途径、细胞壁多糖代谢、蜡质代谢、催化活性等途调，在此基础上，构建了基于lncRNA-激素-氧化还原-细胞壁的番茄裂果调控网络；进一步利用gateway或CRISPR技术，构建了裂果相关的ERF2、XTH、PG、EXP、MAN、miR172等基因的过表达或基因敲除载体，进行了基因遗传转化。明确了与野生型相比，同时抑制调控细胞壁降解的关键基因PG和EXP表达的株系（pg/exp）裂果率降低了16.9%，pg/exp株系果实中原果胶含量更高、细胞壁和角质蜡质层增厚是其裂果率降低的主要原因。该研究丰富了裂果的分子调控网络，可为耐裂果新品种选育提供基因资源，为裂果防控提供指导和方向。