The BAM3 Receptor-Like Kinase Is Required for The Tapetal Development And Pollen Exine Formation

The CLAVATA1(CLV1)-related Leucine-rich repeat receptor-like kinase BAM3 was previously reported to function additively to BAM1/2 in other aspects of plant development. Here we reported the important role of BAM3 in anther development. We demonstrated that in the anther, bam3-2 single mutant exhibited delayed tapetal degradation and a more extensively covered surface through cell biological analyses. Further transcriptomic studies revealed that 813 genes significantly expressed at the RNA level in the bam3-2 mutant compared with wild-type, which were enriched in pollen exine formation, lipid metabolism, lipid transfer, and proteolysis. Moreover, an intersection analysis of significantly regulated genes in bam3-2, DN-CLE19 and ams revealed BAM3, CLE19 and AMS commonly affected the expression level of many genes, especially genes invovled in pollen development such as CYP703A2?LAP6?TKPR2?CYP703B1?MS2?WBC27?MEE48?QRT3?LAP5?DRL1 and MYB103. These results suggested that BAM3 is a crucial executor during tapetum degradation and pollen exine formation and probably takes part in the CLE19-AMS signaling pathway during anther development process.

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