Gene cloning of Zm<scp>MYB</scp>59 transcription factor in maize and its expression during seed germination in response to deep‐sowing and exogenous hormones

Abstract

Abstract Discovering the key genes responsible for deep‐sowing germination is very meaningful to cultivate maize varieties with strong germination ability in soil. In this study, Zm MYB 59 gene whose functions remain unknown was successfully cloned. Subcellular localization showed that Zm MYB 59 was localized in the nucleus. By analysing cis‐acting elements of its promoter sequence, many elements of MYB binding domain responsive to hormones (particularly gibberellin, GA ) were found. On this basis, Zm MYB 59 expression in different sowing depths, germination stages, tissues and treatments was analysed by real‐time PCR . Zm MYB 59 expression levels in embryos or seedlings were significantly decreased with the increase in sowing depth at 2 days or 4 days after sowing ( DAS ). Further analysis showed that its expression in mesocotyls was also significantly downregulated with the increase in sowing depth at both 6 DAS and 8 DAS . Similarly, seed soaking with 10 ‐5 M GA 3 inhibited Zm MYB 59 expression in mesocotyls at 3 DAS . These results suggest that Zm MYB 59 may play a negative regulatory role in seed germination in deep soil and the regulation is involved in GA signalling pathway.