NIN is essential for development of symbiosomes, suppression of defence and premature senescence in Medicago truncatula nodules

• DOI: 10.1111/nph.17215
• Publication Date: 2021-01-20T15:06:31Z
• Authors: Jieyu Liu; Menno Rasing; Tian Zeng; Joël Klein; Olga Kulikova; Ton Bisseling
• Keywords: Medicago truncatula; Senescence

NIN (NODULE INCEPTION) is a transcription factor that plays key role during root nodule initiation. However, its in later developmental stages unclear. Both mRNA and protein accumulated at the highest level proximal part of infection zone Medicago truncatula nodules. Two nin weak allele mutants, nin-13/16, form rather normal zone, whereas fixation not formed. Instead, with defence responses premature senescence occurred symbiosome development gets arrested. Mutations nin-13/16 resulted truncated lacking conserved PB1 domain. this did cause phenotype as mutants expressing NINΔPB1 formed wild-type-like nodule. The likely to be caused by reduced levels cytoplasm. Transcriptome analyses nin-16 nodules showed expression defence/senescence-related genes are markedly increased, suppressing reduced. Although defence/senescence seems well suppressed transcriptome already changed zone. In addition function organogenesis, also major transition from establishing functional symbiosis.