Wehbi Houssein, Soulhat Camille, Morin Halima, Bendahmane Abdelhafid, Hilson Pierre, Bouchabké-Coussa Oumaya
Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France.
Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France.
Plants (Basel). 2022 Apr 14;11(8):1068. doi: 10.3390/plants11081068.
Plant somatic embryogenesis (SE) is a natural process of vegetative propagation. It can be induced in tissue cultures to investigate developmental transitions, to create transgenic or edited lines, or to multiply valuable crops. We studied the induction of SE in the scutellum of monocots with as a model system. Towards the in-depth analysis of SE initiation, we determined the earliest stages at which somatic scutellar cells acquired an embryogenic fate, then switched to a morphogenetic mode in a regeneration sequence involving treatments with exogenous hormones: first an auxin (2,4-D) then a cytokinin (kinetin). Our observations indicated that secondary somatic embryos could already develop in the proliferative calli derived from immature zygotic embryo tissues within one week from the start of in vitro culture. Cell states and tissue identity were deduced from detailed histological examination, and in situ hybridization was performed to map the expression of key developmental genes. The fast SE induction method we describe here facilitates the mechanistic study of the processes involved and may significantly shorten the production of transgenic or gene-edited plants.
植物体细胞胚胎发生（SE）是营养繁殖的自然过程。它可以在组织培养中诱导，用于研究发育转变、创建转基因或编辑品系，或繁殖有价值的作物。我们以单子叶植物的盾片为模型系统研究了体细胞胚胎发生的诱导。为了深入分析体细胞胚胎发生的起始，我们确定了体细胞盾片细胞获得胚胎发生命运的最早阶段，然后在涉及外源激素处理的再生序列中切换到形态发生模式：首先是生长素（2,4-D），然后是细胞分裂素（激动素）。我们的观察表明，从体外培养开始一周内，次生体细胞胚胎就已经可以在源自未成熟合子胚组织的增殖愈伤组织中发育。通过详细的组织学检查推断细胞状态和组织特性，并进行原位杂交以绘制关键发育基因的表达图谱。我们在此描述的快速体细胞胚胎发生诱导方法有助于对相关过程进行机制研究，并可能显著缩短转基因或基因编辑植物的生产时间。
