Effects Of Strigolactone Analogues GR24 On Seedling Growth And Leaf Senescence Of Bambusa Oldhamii

Bambusa oldhamii McClure was a kind of culm and shoot-producing bamboo with high economic value.Reducing the effect of plant hormone strigolactone on shoot growth and development could improve the yeild of culm and shoot of bamboo.The research firstly found that strigolactone analogues GR24 could sustainably inhibited bamboo seedling growth and induced leaf senescence under a high concentration.Then through the analysis of transcriptome data found that both strigolactone biosynthesis and perception associated genes existed in Bambusa oldhamii.After treatment of GR24 the expression of strigolactone perception and leaf senescence associated genes up regulated.GR24 also affected sugar metabolism pathway in shoots,which showed a potential link between strigolactone and sugar.Through experiment on senescence of leaves in vitro confirmed that sugar could inhibit the function of strigolactone on leaf senescence.It indicated that sugar could antagonize the biological function of strigolactone.This paper offered a reference for further study on the influence of sugar and strigolactone interaction on bamboo shoot growth.The results were as follows:(1)Strigolactone analogues GR24 inhibited the increasing of new branches number,shoot length and thickness of Bambusa oldhamii.Only 5 ?M GR24 continued to inhibite seedling growth and induced leaf senescence.(2)6 h after GR24 treatment,gene expression in bud changed significantly.KEGG analysis found that after GR24 treatment metabolic pathway was significantly affected,especially sugar metabolic pathway.Through the further study on the expression of associated genes found that: GR24 promoted the expression of D14 and MAX2 homologous genes,and increased the expression of EIN3 and ARF2 homologous genes which was related to leaf senescence.The expression of genes associated to sugar transport and synthesis also changed significantly.(3)Further study on mature leaf segments found that exogenous sugar significantly inhibited leaf senescence caused by GR24 in darkness,showed sugar inhibited the function of strigolactone.