Figure 2
From: Transgene autoexcision in switchgrass pollen mediated by the Bxb1 recombinase
Activity of the rice pollen-specific promoters PS1 and PS3 in switchgrass pollen. 1–3, Images of switchgrass spikelets showing their morphology at representative developmental stages before anthesis (1–2) and at anthesis (3) corresponding to the stages of pollen development (P1 and P2) and maturation (P3) according to [18]. The stained pollen grains were examined at magnification of 63×.