Figure 4

The expression pattern of GmBEHL1. (a–c) qRT-PCR analysis of GmBEHL1. (a) Seven-day-old seedlings were inoculated with B. japonicum strain USDA110; roots, leaves, and nodules harvested at 28 DAI were used for gene expression analyses (n = 15). (b) Inoculated roots were harvested at 0, 1, 3, 6, 12, and 24 HAI and the expression of GmBEHL1 at the early stage of nodulation was analyzed. (c) The GmBEHL1 expression pattern during nodulation was analyzed using root samples harvested at 0, 1, 3, 5, and 10 DAI (n = 15). GmELF1b was used as an endogenous control for gene expression. The expression levels are shown as the means ± SDs from three replicates. Means with different letters are significantly different (p < 0.05; Tukey’s test). (d–i) Histochemical localization of GUS activity in the transgenic hairy roots and at different stages of nodulation. (d and e) Expression pattern of GmBEHL1pro:GUS in primary (d) and lateral roots (e). (f–i) GmBEHL1pro:GUS activity at different stages of soybean nodulation. (f and g) GUS activity during nodule initiation (f) and primordia formation (g). (h,i) GUS staining of GmBEHL1pro:GUS in young nodule at 14 DAI (h) and in paraffin section of young nodule (i); (j,k) GUS staining of mature nodule at 28 DAI (j) and paraffin section of the stained mature nodule (k). Bars in (d–k) = 200 μm.