Molecular Cloning And Functional Analysis Of A Male Sterile Gene MS157 In Arabidopsis

The dysfunction of tapetum cells in differentiation and secreting usually results in abnormal formation and sterility of the pollen in plants. Callose formation and dissolution during and after meiotic division is a unique feature of male meiosis and is important for pollen development. In this work, we reported molecular cloning of a putative bHLH transcription factor MS157 which regulates callose dissolution during anther development in Arabidopsis. In previous work, male sterile mutant ms157 was isolated using an ethyl methane sulphonate mutagenized strategy and MS157 was mapped to a region of 74 kb located in BAC clone T6K22 on chromosome IV. Sequence analysis reveals that there are three bases variation in the coding region of at4g21330, resulting in three amino acid changes. Genetic complementation and allele analysis both confirmed that the mutations of at4g21330 lead to male sterile phenotype. Cytological observations showed the defective of the tapetum and middle layer development. Anine blue staining showed callose dissolution was defected in ms157. RT-PCR and Real-Time PCR analysis showed that callose dissolution related gene A6 was down-regulated in the mutant anther. These results suggest that MS157 plays an important role in anther development by regulating callose dissolution.