Fig. 1

Development of transgenic cotton embryogenic calli with OsLOL1 overexpression and empty vector. a PCR detection of transgenic cotton embryogenic calli. M: DNA marker; P: positive control, the plasmid with OsLOL1 gene; N: non-transgenic cotton plants; 1–18: various independent embryogenic calli. b Days of transition from somatic callus to embryogenic callus. NP: samples with empty vector, OE: those with OsLOL1. Bar values (SD) are calculated through three biological repeats. Double asterisks represent extremely significant differences (P < 0.01) by Student’s t-test. c and d Relative expression levels of OsLOL1 (c) and NPT II (d). OE1–10: those with OsLOL1 overexpression, NP1–10: the embryogenic calli with empty vector. GhUbi gene was used as internal control for normalization. The expression levels of OE1 and NP1 are arbitrarily regarded as “1”, respectively. Bars represent SD from biological repeats