Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.09.21.307009v1?rss=1 Authors: Wu, G., Wei, X., Wang, X., Liang, X., Wei, Y. Abstract: Mature embryos were used as explant for embryogenic callus (EC) induction, and then EC further developed to form somatic embryos during somatic embryogenesis (SE) of Ormosia henryi Prain, however, some mature embryos could induced non embryogenic callus (NEC), browning callus (BC) or snowflake callus (SC). The present study was carried out to analyse the biochemical events and histochemical changes at different SE stages in 0. henryi. The contents of their energy substances, H2O2, endogenous hormones and enzyme activities were measured. The results showed that the contents of soluble sugar, starch, the activities of PPO, SOD, APX, POD, the ratios of IAA/ABA, IAA/GAs, AUX/GAs, AUX/ABA decreased gradually at different SE stages; in contrary, the contents of soluble protein, H2O2, all kinds of endogenous hormones increased gradually; however, CAT activity and the ratios of IAA/CKs, AUX/CKs, ABA/CKs, GAs/CKs increased first and then decreased. The high contents of GAs, ABA, the high ratios of ABA/CKs, GAs/CKs and the low ratios of IAA/ABA, IAA/GAs, AUX/GAs, AUX/ABA were the reasons why callus could not form EC. The low enzyme activities, the low contents of energy substances and H2O2 were related to the NEC formation; the high contents of soluble sugar, H2O2, AUX, CKs and PPO activity and the low conent of soluble protein were the basic reasons for BC formation; the high energy substances contents and the low activities of SOD, POD were easy to form SC. Copy rights belong to original authors. Visit the link for more info