Expression Of JA-related Genes Research Articles

Transcriptional landscape of pathogen-responsive lncRNAs in tomato unveils the role of hydrolase encoding genes in response to Botrytis cinerea invasion.

LncRNAs have gained increasing attention owing to their important regulatory roles on growth and stress responses of plants. However, the mechanisms underlying the functions of lncRNAs in fruit-pathogen interaction are still largely unknown. In this study, a total of 273 lncRNAs responding to Botrytis cinerea infection were identified in tomato fruit, among which a higher percentage of antisense lncRNAs were targeted to the genes enriched in hydrolase activity. To ascertain the roles of these lncRNAs, seven hydrolase-related transcripts were transiently knocked-down by virus-induced gene silencing. Silencing of lncRNACXE20 reduced the expression level of a carboxylesterase gene, further enhancing the resistance of tomato to B. cinerea. In contrast, silencing of lncRNACHI, lncRNAMMP, lncRNASBT1.9 and lncRNAPME1.9 impaired the resistance to B. cinerea, respectively. Further RT-qPCR assay and enzymatic activity detection displayed that the attenuated resistance of lncRNAMMP and lncRNASBT1.9-silenced plants was associated with the inhibition on the expression of JA-related genes, while the decreased resistance of lncRNACHI-silenced plants resulted in reduced chitinase activity. Collectively, these results may provide references for deciphering the mechanisms underlying specific lncRNAs to interfere with B. cinerea infection by regulating the expression of defence-related genes or affecting hydrolase activity.

Variation in both host defense and prior herbivory can alter plant-vector-virus interactions

BackgroundWhile virus-vector-host interactions have been a major focus of both basic and applied ecological research, little is known about how different levels of plant defense interact with prior herbivory to affect these relationships. We used genetically-modified strains of tomato (Solanum lycopersicum) varying in the jasmonic acid (JA) plant defense pathways to explore how plant defense and prior herbivory affects a plant virus (tomato yellow leaf curl virus, ‘TYLCV’), its vector (the whitefly Bemisia tabaci MED), and the host.ResultsVirus-free MED preferred low-JA over high-JA plants and had lower fitness on high-JA plants. Viruliferous MED preferred low-JA plants but their survival was unaffected by JA levels. While virus-free MED did not lower plant JA levels, viruliferous MED decreased both JA levels and the expression of JA-related genes. Infestation by viruliferous MED reduced plant JA levels. In preference tests, neither virus-free nor viruliferous MED discriminated among JA-varying plants previously exposed to virus-free MED. However, both virus-free and viruliferous MED preferred low-JA plant genotypes when choosing between plants that had both been previously exposed to viruliferous MED. The enhanced preference for low-JA genotypes appears linked to the volatile compound neophytadiene, which was found only in whitefly-infested plants and at concentrations inversely related to plant JA levels.ConclusionsOur findings illustrate how plant defense can interact with prior herbivory to affect both a plant virus and its whitefly vector, and confirm the induction of neophytadiene by MED. The apparent attraction of MED to neophytadiene may prove useful in pest detection and management.

Monitoring of Rice Transcriptional Responses to Contrasted Colonizing Patterns of Phytobeneficial Burkholderia s.l. Reveals a Temporal Shift in JA Systemic Response.

In the context of plant–pathogen and plant–mutualist interactions, the underlying molecular bases associated with host colonization have been extensively studied. However, it is not the case for non-mutualistic beneficial interactions or associative symbiosis with plants. Particularly, little is known about the transcriptional regulations associated with the immune tolerance of plants towards beneficial microbes. In this context, the study of the Burkholderia rice model is very promising to describe the molecular mechanisms involved in associative symbiosis. Indeed, several species of the Burkholderia sensu lato (s.l.) genus can colonize rice tissues and have beneficial effects; particularly, two species have been thoroughly studied: Burkholderia vietnamiensis and Paraburkholderia kururiensis. This study aims to compare the interaction of these species with rice and especially to identify common or specific plant responses. Therefore, we analyzed root colonization of the rice cultivar Nipponbare using DsRed-tagged bacterial strains and produced the transcriptomes of both roots and leaves 7 days after root inoculation. This led us to the identification of a co-expression jasmonic acid (JA)-related network exhibiting opposite regulation in response to the two strains in the leaves of inoculated plants. We then monitored by quantitative polymerase chain reaction (qPCR) the expression of JA-related genes during time course colonization by each strain. Our results reveal a temporal shift in this JA systemic response, which can be related to different colonization strategies of both strains.