2,4-dichlorophenoxyacetic acid (2,4-D), an auxinic herbicide, in many in vitro somatic embryogenesis systems is used to induce embryogenesis. This compound present at a low concentration (0.5 µM) during the induction phase, is necessary for M. truncatula embryogenic callus formation and, consequently, for embryo development. 2,4-D in higher concentration (5 µM) causes an increase in O₂^·− accumulation which disturbs the callus and embryos formation. However, above processes are disturbed by DPI, an inhibitor of the NADPH oxidase responsible for the O₂^·− production. Thus, the aim of this study was to elucidate whether during first week of induction phase the change in the level of O₂^·− affects the expression of genes encoding Polycomb and Trithorax group proteins and the transcription level of some marker genes for SE. The expression of Polycomb and Trithorax group genes, and coding the transcription factors such as: LEC1, L1L, WUS, WOX5 and STM depends on the O₂^·− accumulation in explant cells. Disorder of its level by manipulation of the concentration of 2,4-D or DPI disrupts expression of the above-mentioned genes and causes disturbances in the callus growth and development of somatic embryos.

2,4-二氯苯氧基乙酸（2,4-D），一种生长素除草剂，在许多体外体细胞胚发生系统中被用来诱导胚发生。该化合物在诱导期以低浓度（0.5 µM）存在，对于截短支原体胚发生的愈伤组织形成，因此对于胚胎发育是必需的。较高浓度（5 µM）的2,4-D导致O ₂ ^·-积累增加，从而干扰了愈伤组织和胚胎的形成。然而，上述过程由DPI干扰，所述NADPH的抑制剂氧化酶负责将O ₂ ^{· -}的生产。因此，本研究的目的是阐明在诱导期的第一周内O ₂ ^·-的水平是否发生变化。影响编码Polycomb和Trithorax组蛋白的基因的表达以及SE的某些标记基因的转录水平。的表达多梳和Trithorax组基因，和编码的转录因子如：LEC1，L1L，WUS，WOX5和STM取决于将O ₂ ^{· -}中的外植体细胞中的积累。通过控制2，4-D或DPI的浓度使其水平紊乱破坏了上述基因的表达，并导致了体细胞胚的愈伤组织生长和发育的紊乱。