The natural immune system has undergone tremendous changes since the birth of the newborn. Then, after the seed germination, it is unclear whether the plant's natural immune system will gradually mature with the growth of the seedling. Lv Dongping’s Group found that the immune response mediated by the immunoreceptor FLS2 is continuously enhanced during the growth of Arabidopsis seedlings, indicating that the plant’s natural immune system undergoes a step by step process, which is controlled by the transcription of the flagellin-sensitive2 (FLS2) gene. Further studies showed that two AP2 transcription factors, TOE1 and TOE2, bind directly to the promoter of the FLS2 gene and inhibit transcription of the FLS2 gene. TOE1 and TOE2 are known to be target genes of microRNA172 (miR172). Further studies revealed that during the growth of Arabidopsis seedlings, the abundance of miR172 increased gradually while the protein accumulation of TOE1 and TOE2 decreased. Therefore, the inhibition of FLS2 transcription by TOE1 and TOE2 was gradually reduced, which led to the expression of FLS2 gene during the growth of the seedlings gradually increased, eventually leading to the establishment of the FLS2-mediated natural immune system (Ontogeny).

The study believes that the characteristics of plant natural immunity in the early stage of seedling development may be the adaptation of plants to the rapid growth of this stage, which is the result of resource and energy balance between immunity and development. This research has given people a new understanding of the establishment of the immune system, immunity and age, and the relationship between immunity and development.

The results of the study were published online October 18, 2018 in The Plant Cell (DOI: 10.1105/tpc.18.00297). The research was funded by the “973” program of the Ministry of Science and Technology, the National Natural Science Foundation of China, and the State Key Laboratory of Plant Genomics.

Source: Institute of Genetics and Developmental Biology

Time: 2018.10.23