Plant Physiology, Biotechnology Institute of Asturias (IUBA), Department of Organisms and Systems Biology, University of Oviedo, ES-33071 Oviedo, Spain.
Plant Physiology, Department of Engineering and Agricultural Sciences, University of León, ES-24071 León, Spain.
Genes (Basel). 2021 Mar 19;12(3):438. doi: 10.3390/genes12030438.
Conifers are a group of woody plants with an enormous economic and ecological importance. Breeding programs are necessary to select superior varieties for planting, but they have many limitations due to the biological characteristics of conifers. Somatic embryogenesis (SE) and de novo organogenesis (DNO) from in vitro cultured tissues are two ways of plant mass propagation that help to overcome this problem. Although both processes are difficult to achieve in conifers, they offer advantages like a great efficiency, the possibilities to cryopreserve the embryogenic lines, and the ability of multiplying adult trees (the main bottleneck in conifer cloning) through DNO. Moreover, SE and DNO represent appropriate experimental systems to study the molecular bases of developmental processes in conifers such as embryogenesis and shoot apical meristem (SAM) establishment. Some of the key genes regulating these processes belong to the and homeobox gene families, whose function has been widely described in . The sequences and roles of these genes in conifers are similar to those found in angiosperms, but some particularities exist, like the presence of , a gene that putatively participates in the establishment of SAM in somatic embryos and plantlets of .
针叶树是一类具有巨大经济和生态重要性的木本植物。为了选择优良品种进行种植，需要进行育种计划，但由于针叶树的生物学特性，这些计划存在许多限制。体胚发生（SE）和体外培养组织的从头器官发生（DNO）是两种植物大量繁殖的方法，可以帮助克服这个问题。虽然这两个过程在针叶树中都很难实现，但它们具有高效率、可以冷冻保存胚性系以及通过 DNO 繁殖成年树木（针叶树克隆的主要瓶颈）的优势。此外，SE 和 DNO 代表了研究针叶树发育过程（如胚胎发生和茎尖分生组织（SAM）建立）的分子基础的合适实验系统。一些调节这些过程的关键基因属于 Homeobox 基因家族，其功能在被子植物中得到了广泛描述。这些基因在针叶树中的序列和功能与在被子植物中发现的相似，但存在一些特殊性，例如存在 ，这是一个假定参与体细胞胚和 植株 SAM 建立的基因。
