Abstract: MLPK（M-locus protein kinase）is a positive key mediator of Brassica self-incompatibility signaling，however，the molecular mechanism of MLPK in mediating Brassica self-incompatibility response is still unknown. Meanwhile，the downstream factors of Brassica self-incompatibility signaling still need to be isolated. Aim to explore the idea and methods to isolate MLPK-interacting proteins，here，the MLPK truncated protein MLPK-T lack of the plasma membrane localization motif was constructed，the interaction of MLPK with ARC1 was proved via conventional yeast two-hybrid system. Then，we obtained 96，101，70 and 62 PUB proteins from B. olercea，B. rapa，Arabidopsis lyrata and A. thaliana through genome-wide identification，amount to 127 PUB proteins containing ARM repeat domains. Based on phylogenetic analysis，we selected 8 PUB proteins，and RT-PCR showed that all these 8 genes expressed in B. oleracea stigmas. Finally，the interaction of MLPK with Bol008579，Bol016165 and Bol023511 were proved through yeast two-hybrid system.

Key words: Brassica oleracea, self-incompatibility, M-locus protein kinase, plant U-box protein, gene family, interaction, tomato, SELF-PRUNING, gene, shoot architecture, regulatory, growth habit