Abstract: We used 14 Arabidopsis thaliana transgenic reporter lines  to investigate the mechanism of leukamenin E regulating the expression of polar auxin carriers and affecting root growth and development. The results showed that leukamenin E within 20-40 μmol·L^-1 significantly inhibited the growth of primary roots of A. thaliana seedlings. However, low concentration of leukamenin E (10 μmol·L^-1) promoted the early occurrence of lateral roots and increased the number of lateral roots. Leukamenin E significantly increased auxin level in the root apex at 10-30 μmol·L^-1 for 48 h. Furthermore, we investigated the role of leukamenin E in response to polar auxin transport proteins in A. thalianaroots. The results showed that expression of PIN1was upregulated and expression of PIN2was downregulated at the transcriptional and protein level by leukamenin E. The abundance of PIN3, PIN7, and PIN4 were obviously reduced in the columella cells and the quiescent center and surrounding cells. The abundance of AUX1 was decreased in the epidermis and lateral root cap cells. These results suggest that auxin accumulation in the root apex through regulation of polar auxin carriers had inhibitory effects on primary roots and early formation of lateral roots.

Key words: Phyllostachys violascens, mulching of bamboo stand, non-structural carbohydrates (NSC), N, P.