Table 1. Quantitative analysis of endogenous BR intermediates in creeping bentgrass.

BRs	NT	AtBAT1 #3	AtBAT1 #4
Typhasterol (TY)	7.36/6.86	3.22/3.31	3.46/3.91
6-deoxocastasterone (6-deoxoCS)	9.40/9.16	5.40/5.44	4.83/5.62
Castasterone (CS)	7.10/5.10	3.48/2.51	3.62/3.12
Brassinolide (BL)	n.d.	n.d.	n.d.

Endogenous BR levels were measured by GC-SIM using [26, 28-²H₆]-labeled BRs as internal standards. The leaves of 5-week-old plants in soil were used in these analyses, and the contents (ng/g fresh weight) of BR intermediates are shown, which were obtained from two independent experimental measurements (shown as the first result/the second result). NT, Non-transformed creeping bentgrass; AtBAT1 #3 and #4, two transgenic creeping bentgrass plants overexpressing AtBAT1; n.d., not detected (i.e., below the detection limit).