Fig. 9

TaLOX3 expression is altered by TaWRKY42-B, MeJA treatment, and the senescence process. a Expression level of TaLOX3 in TaWRKY42-B-silencing plants. b Transcription of TaLOX3 was detected after MeJA treatment. Seven-day-old wheat seedlings were treated with 200 μM MeJA for 1, 2 and 3 h. c-e Expression pattern of senescence-associated genes TaSAG3, TaSAG5, and TaLOX3 at different developmental stages of wheat flag leaves (M, ES, and LS). f Proposed model of the TaWRKY42-B-mediated regulatory network of leaf senescence. TaWRKY42-B functions as a promoter of leaf senescence through activating a putative JA biosynthesis gene, TaLOX3, which is also induced by JA signaling. When plants are at the juvenile stage, high levels of TaWRKY42-B are likely responsible for JA-related developmental regulation and biosynthesis. While wheat plants advance into the senescent stage, leaf senescence suppresses the TaWRKY42-B-TaLOX3 module for normal progression of leaf senescence. The feedback control of TaWRKY42-B by JA signaling, and leaf senescence has the potential to be a vital step of timing of leaf senescence. (Error bars indicate SD. Asterisks indicate significant differences. Student’s t-test, *P < 0.05, **P < 0.01)