Molecular mechanism involved in maleic hydrazide-mediated sucker control
Molecular signals from the shoot apical meristem (SAM) mediate a hormonal signal that effectively inhibits axillary bud growth. Upon removal of the SAM, the hormonal signal is lost and enables axillary buds to grow into new shoots (or “suckers”) resulting in yield loss and poor leaf quality. Sucker control chemical applications are critical for managing sucker growth following plant topping. Predominantly, maleic hydrazide (MH) has been used to manage sucker growth as a systemic sucker control reagent. After application, maleic hydrazide is absorbed by leaves and translocated through the plant to small sucker buds. The inhibitory effect of MH on sucker growth is considered to be the result of the suppression of plant metabolism (inhibition of enzymatic activity) and interference of the compound with plant hormones and growth regulators. MH also acts as an inhibitor of the synthesis of nucleic acids and proteins. Understanding the mechanism of MH on sucker suppression may provide additional insights for the development of non-chemical sucker control. In this study, transcriptome profiles were carried out before and after MH treatments. Differential expression analysis showed that several cell cycle genes were inhibited from MH treated plants compared to controls. Experiments are in progress to evaluate these cell cycle genes with sucker specific promoters.