Fig. 4.

Male and female infertility phenotypes of the biallelic Vuspo11-1 mutant. a Diagram of partial SPO11-1 gene structure (four of 15 exons in grey) and the gene editing target sites in exon 1 and exon 3 in yellow. The protospacer adjacent motif (PAM) site is underlined and in bold. The Cas9 cleavage site is indicated with scissors and sequences altered in the biallelic Vuspo11-1-edited plant are shown in pink. b Floral buds of cowpea IT86D-1010 at stage 1F-IX [38], isolated gynoecia and anthers of wild-type at left and the biallelic Vuspo11-1 mutant, right. Insets show anthers of WT (left) and Vuspo11-1 mutant (right). c Viability of pollen grains at stage 1F-IX using iodine-potassium iodide staining WT and d biallelic Vuspo11-1 mutant pollen grains. Intense dark brown indicates viable pollen. e WT and fVuspo11-1 mutant pollen grains observed using DIC microscopy. g–j Mature female gametophytes showing normal development in WT g and i, and degeneration in Vuspo11-1 mutant ovules h and j. Scale bars b = 0.5 cm, c, d = 100 µm, e, f = 20 µm, g, h = 50 µm. CC central cell, EC egg cell, MES mature embryo sac, PN polar nuclei