Oulbi Sara, Kohaich Kaoutar, Baaziz Mohammed, Belkoura Ilham, Loutfi Kenza
Laboratoire d'Agroalimentaire, Biotechnologies et Valorisation des Bio-Ressources Végétales, Faculté des Sciences Semlalia, Université Cadi Ayyad, BP 2390, Marrakech 40000, Morocco.
Laboratoire de Culture In Vitro, Département des Sciences de Base, Ecole Nationale d'Agriculture, BP S/40, Meknes 50001, Morocco.
Plants (Basel). 2021 Apr 29;10(5):901. doi: 10.3390/plants10050901.
As part of the search for biochemical markers of somatic embryogenesis in tissue cultures of olive ( L.), peroxidases (POXs) in both the soluble and ionically wall-bound fractions were studied in two reputed olive cultivars (cvs.): "Picholine Marocaine" and "Dahbia". In order to carry out embryogenesis induction, proximal cotyledons were cultured in modified olive medium (OMc) supplemented with 25 μM indole-3-butylic acid (IBA) and 2.5 μM 2-isopentenyladenine (2iP), while distal leaf fragments (somatic explants) were cultured in OMc supplemented with 4.56 µM zeatin riboside (ZR) and 10.25 µM 1-naphthaleneacetic acid (NAA). Regarding embryogenic potentials, the zygotic explants (cv. Picholine Marocaine: 43.39%; cv. Dahbia: 53.41%) were more regenerative than the somatic explants (cv. Picholine Marocaine: 13.05%; cv. Dahbia: 19.51%). The enzyme assay showed a higher POX activity in embryogenic calluses (ECs) than in nonembryogenic calluses (NECs) for the zygotic explants in both studied cultivars. When expressed as units per milligram of proteins (U mg proteins), the highest total POXs activities (soluble POXs + ionically wall-bound POXs) were found in the ECs derived from the zygotic explants; for cv. Dahbia, 65% of the enzyme activities came from the ionically wall-bound fractions. Polyacrylamide gel electrophoresis showed that the ECs of the highly active cv. Dahbia were characterized by highly active isoperoxidases that were revealed in four migration zones, particularly a doublet in the A4 zone (R 0.70-0.73) present in the ionically wall-bound POXs. The fast-moving anodic POXs of the ionically wall-bound fractions could be adopted as an early electrophoretic test to determine the embryogenesis capacities in olive tissue culture materials. As biochemical markers, the POX enzyme and its profile in fractions, i.e., as soluble POXs and ionically wall-bound POXs, can offer a valuable tool for improving the tissue culture of olive via somatic embryogenesis.
作为寻找油橄榄（Olea europaea L.）组织培养中体细胞胚胎发生生化标记物的一部分研究，对两个著名油橄榄品种“皮肖利纳·摩洛哥”和“达比亚”的可溶性和离子结合在细胞壁上的过氧化物酶（POXs）进行了研究。为了诱导胚胎发生，将近端子叶在添加了25 μM吲哚-3-丁酸（IBA）和2.5 μM 2-异戊烯基腺嘌呤（2iP）的改良油橄榄培养基（OMc）中培养，而远端叶片片段（体细胞外植体）在添加了4.56 µM玉米素核苷（ZR）和10.25 µM 1-萘乙酸（NAA）的OMc中培养。关于胚胎发生潜力，合子外植体（“皮肖利纳·摩洛哥”品种：43.39%；“达比亚”品种：53.41%）比体细胞外植体（“皮肖利纳·摩洛哥”品种：13.05%；“达比亚”品种：19.51%）具有更强的再生能力。酶活性测定表明，在两个研究品种的合子外植体中，胚性愈伤组织（ECs）中的POX活性高于非胚性愈伤组织（NECs）。以每毫克蛋白质的单位数（U mg蛋白质）表示时，在合子外植体来源的ECs中发现了最高的总POXs活性（可溶性POXs + 离子结合在细胞壁上的POXs）；对于“达比亚”品种，65%的酶活性来自离子结合在细胞壁上的部分。聚丙烯酰胺凝胶电泳显示，高活性的“达比亚”品种的ECs具有高活性的同功过氧化物酶，在四个迁移区显示出来，特别是在离子结合在细胞壁上的POXs中的A4区（Rf 0.70 - 0.73）有一个双峰。离子结合在细胞壁上部分的快速移动阳极POXs可作为一种早期电泳测试，用于确定油橄榄组织培养材料中的胚胎发生能力。作为生化标记物，POX酶及其在各部分的图谱，即可溶性POXs和离子结合在细胞壁上的POXs，可为通过体细胞胚胎发生改善油橄榄组织培养提供有价值的工具。
