Over-Expression of the Cell-Cycle Gene LaCDKB1;2 Promotes Cell Proliferation and the Formation of Normal Cotyledonary Embryos during Larix kaempferi Somatic Embryogenesis

Abstract

Somatic embryogenesis is an effective tool for the production of forest tree seedlings with desirable characteristics; however, the low initiation frequency and productivity of high-quality mature somatic embryos are still limiting factors for Larix kaempferi (Japanese larch). Here, we analyzed the expression pattern of L. kaempferi cyclin-dependent kinase B 1;2 (LaCDKB1;2) during somatic embryogenesis in L. kaempferi and its relationship with the cell proliferation rate. We also analyzed the effect of LaCDKB1;2 over-expression on somatic embryo quality. The results revealed a positive correlation between LaCDKB1;2 expression and the cell proliferation rate during the proliferation stage. After LaCDKB1;2 over-expression, the proliferation rate of cultures increased, and the number of somatic embryos in transgenic cultures was 2.69 times that in non-transformed cultures. Notably, the number of normal cotyledonary embryos in transgenic cultures was 3 times that in non-transformed cultures, indicating that LaCDKB1;2 not only increases the proliferation of cultures and the number of somatic embryos but also improves the quality of somatic embryos. These results provide insight into the regulatory mechanisms of somatic embryogenesis as well as new Larix breeding material.

VS-Cambium-Developer: A New Predictive Model of Cambium Functioning under the Influence of Environmental Factors

“…Similar gradients have been observed for several cyclins [26][27][28][29][30]. Moreover, it also shows a relationship between the influence of external climatic factors and cell cycle gene expression [25,[31][32][33][34][35].…”

“…A broad range of literature suggests that the balance of auxins and cytokinins may be involved in the r ulation of cambial activity [15][16][17][18][19][20][21] as well as the balance of substrates (sugars) and zymes [19,[22][23][24][25]. Similar gradients have been observed for several cyclins [26-3 Moreover, it also shows a relationship between the influence of external climatic fact and cell cycle gene expression [25,[31][32][33][34][35].…”

LkARF7 and LkARF19 overexpression promote adventitious root formation in a heterologous poplar model by positively regulating LkBBM1

“…Here, it was found that the sequence similarity of ARF7/19 between larch and poplar was greater than that of Arabidopsis , so poplar was used to study the function of LkARF7/19 in AR formation. Now, transformed larch embryonic cells 61 , 62 have been obtained and gene editing has been performed in larch protoplasts 63 , giving us more opportunities to study the function of LkARF7/19 in larch.…”

Long-Term Successional Subculture Dynamics and Their Effects on the Proliferation Efficiency, Embryogenic Potential, and Genetic Stability of Embryogenic Tissues in Larix principis-rupprechtii Mayr

“…and techniques to enhance culture efficiency across various Pine species have been explored [10,[12][13][14][15][16][17][18][19][20]. Furthermore, with the advancement of bioinformatics, researchers are increasingly focusing on the role of genes involved in the various stages of somatic embryogenesis [8,[21][22][23]. However, studies have shown that some conifer somatic cells exhibit reduced proliferation efficiency and even loss of maturation capability after long-term ex vivo culture [24,25].…”