Giving maize an excited start-Effects of dopamine on maize germination

摘要

Dopamine(DA)is a neurotransmitter which takes charge of brain activities about memory and self-stimulation behavior in animals.Interestingly,our results suggest that DA could also give maize an“excited state”.The results showed that 1 mmol L–1 DA promoted maize germination by 23.2%significantly,and accelerated the growth rate of roots and shoots by 21.4 and 24.7%,respectively.As we all known,abscisic acid(ABA)is the key hormone involved in seed dormancy.In our research,ABA levels in roots and shoots dramatically decreased by 16.45 and 57.57%,respectively.To further investigate how DA reduces the ABA level in budding seed,we studied ABA synthesis and catabolism pathway.Specific expression of key ABA-synthesis genes,such as ZmNCED1,ZmNCED3 and ZmZEP were down-regulated by DA.Simultaneously,the expression levels of ABA8OX1a and ABA8OX1b which are major transcripts of ABA 8´-hydroxylase in ABA catabolism were up-regulated at least 1.5-and 4.6-fold,respectively.Our results enriched the functions of animal hormones in plants.