Gnawing pressure led to the expansion of JAZ genes in angiosperms

A long-standing problem in evolutionary biology is why some populations differentiate into many species while the majority do not. Angiosperms is an excellent group for investigating this problem because their diversity is unevenly distributed in space and phylogeny. Plant hormone participates in growth, development and defense. However, jasmonic acid (JA) was the only hormone response to bites. We first searched jasmonate ZIM-domain (JAZ), AUXIN/INDOLE ACETIC ACID (IAA / aux), PYR/PYL/RCAR (PYL), DELLA, and SUPPRESSOR OF MAX2 1-like (SMAX) in 272 plant species. We found the gene number change trends were consistent with origination rates and species numbers of angiosperms. So, 26 representative species were selected as an example for further analysis. The results showed JAZ had experienced two lineage-specific gene expansion events in angiosperms, which coincided with increases in mammalian body size and dental diversity. The proliferation of large herbivores as a results of mammalian prosperity after dinosaur extinction may be related to angiosperm evolution and bursting. The proliferation of large herbivores as the result of mammalian prosperity after the extinction of the dinosaurs was related to angiosperm evolution and bursting. Overall, our study uncovered a previously unknown co-evolution mechanism in terrestrial plants exposed to extreme environmental conditions.