Fig. 5

Functional verification of OscpSRP54b for chloroplast development. a Deletion mutation at the target site in three representative knockout lines generated by the CRISPR/Cas9-mediated editing. cr1–2, cr1–5 and cr2–3 are homozygous mutants carrying 1-bp deletion on both homochromosomes. Black boxes indicate exons and lines indicate introns of OscpSRP54b. The sgRNA target sequence is underlined in blue and the PAM motif is highlighted in red letters, F and R are the forward and reverse primers for qRT-PCR analysis; b Phenotype of Kitaake and OscpSRP54b knockout mutants. Bar = 2 cm; c Pigment contents in 1 week-old leaves of Kitaake, cr1–2 and cr2–3. Different letters indicate significant differences according to One-way ANOVA and Duncan’s test (p ≤ 0.01); Chloroplast ultrastructure of Kitaake (d), cr1–2 (e) and cr2–3 (f). G, grana thylakoid; S, starch granule; OG, osmiophilic plastoglobuli; SL, stroma lamellae; HV, hollow vesicle