Expression analysis of GhL1L1. (a) qRT‐PCR analysis of GhL1L1 (0, 6, 24, 48 h and 5 days explants; NEC, nonembryogenic callus; EC, embryogenic callus; SGE, somatic globular embryo; STE, somatic torpedo embryo; SCE, somatic cotyledon embryo; ZGE, zygotic globular embryo; ZTE, zygotic torpedo embryos; ZCE, zygotic cotyledon embryo). (b) qRT‐PCR analysis of GhL1L1 in YZ1, Jin668, Simian3 and H7124. (c) Southern blotting of transgenic cotton plants, OE4 and OE9 represent the overexpression lines, Ri1, Ri2 and Ri3 represent RNA interference of 3′ untranslated region lines, Ri21and Ri27 represent RNA interference of coding region lines. (d) qRT–PCR analysis of GhL1L1 in different transgenic and null lines in leaf, shoot apical meristem (SAM), 7, 25, 40 days explants and ECs. (e) Northern blot analysis of GhL1L1 in different transgenic and null lines in ECs and leaf. The data (in a, b and d) are shown as the mean ± SE (n = 3).