Fig. 4

a In vitro organogenesis of tobacco on MS medium supplemented with NAA (0.01 mg/l) and BAP (1.0 mg/l) phytohormones. Three different concentrations i.e., minimal (Mi; <0.1 mM), optimal (O; 0.1 mM) and maximal (Mx; >0.1 mM) of micro-nutrient Boron was supplied with MS medium and leaf explants were cultured. b Induction of shoot primordia on the edges of leaf explants after15 days of culture on MS shoot induction medium. c An enlarged view of a microscopic shoot meristem (shown by an arrow) which was harvested for meristem-determinacy gene expression analysis. d Temporal expression of CLV1 gene analyses in 7 days and 15 days old shoot primordia harvested from explants cultured on minimal, optimal and maximal boron- supplemented medium. Similarly, semi-quantitative expression of WUS gene was analysed in 7 days and 15 days shoot primordia harvested from explants cultured on minimal, optimal and maximal boron- supplemented medium. e Average expression values of CLV1 and WUS genes in shoot primordia after 7 days and 15 days of culture, measured by densitometry imaging analysis avoiding any biases visible in the band intensities on an agarose gel