Fig. 1

Response of OsVPE2 expression to low temperature and its regulation of chilling tolerance and yield characters. AOsVPE2 gene expression pattern in response to chilling treatment. The value of “0 h” was set to 1. B Relative expression levels of OsVPE2 overexpression lines (OE-1 and OE-2) and wild-type XZX31. The expression level in the wild-type XZX31 was set to 1. C CRISPR/Cas9 mediated mutagenesis of OsVPE2. Top panel: gene structure of OsVPE2. Exons, introns and the 5’- and 3’-UTRs are represented by blue boxes, black lines and open boxes, respectively. The bottom panel shows alignment of WT and OsVPE2-knockout mutants’ sequences. The sgRNA targets are highlighted in blue and protospacer-adjacement motif (PAM) sequences are indicated in blue font and underlined. The missing bases of sgRNA targets and PAM sequences in the knockout mutants are represented by red dash-lines while other missing bases are indicted by black dash-lines. The inserted bases in mutants are highlighted in red font, while the corresponding position in WT of the inserted base is represented by a blue short line. The sequence gap length is shown in parentheses. D The evaluation of protein translation in OsVPE2-knockout mutants along with WT. The font in red color shows variation in amino acids (aa), whereas short-dash lines indicate missing amino acids. The ellipsis at the C-terminus of the WT OsVPE2 protein represents more amino acids up to 501 aa, while the Stop mark at the end of the mutants’ protein sequences represents early termination. E-F The chilling tolerance phenotype and survival rates of OsVPE2-overexpressing and knockout mutant seedlings, respectively. Bar, 5 cm. Mean and stand deviation are given by three independent experiments. G Seed setting rates, number of tillers per plant and grain weight of the above plant materials. ^{* *}P < 0.01, (compared with WT; Student’s t-test)