Zhao Ye, Guo Qi, Cao Sen, Tian Yanting, Han Kunjin, Sun Yuhan, Li Juan, Yang Qingshan, Ji Qingju, Sederoff Ronald, Li Yun
Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, College of Biological Sciences and Technology, National Engineering Research Center of Tree Breeding and Ecological Restoration, Engineering Technology Research Center of Black Locust of National Forestry and Grassland Administration, Beijing Forestry University, Beijing, China.
Natural Resources and Planning Bureau of Yanshan County, Cangzhou, Hebei, China.
Front Plant Sci. 2022 Sep 20;13:994154. doi: 10.3389/fpls.2022.994154. eCollection 2022.
The AlkB homologs () gene family regulates N-methyladenosine (mA) RNA methylation and is involved in plant growth and the abiotic stress response. Poplar is an important model plant for studying perennial woody plants. Poplars typically have a long juvenile period of 7-10 years, requiring long periods of time for studies of flowering or mature wood properties. Consequently, functional studies of the genes in species have been limited. Based on sequence similarity with , 23 were identified in the genome of the poplar 84K hybrid genotype ( × var. ), and gene structures and conserved domains were confirmed between homologs. The PagALKBH proteins were classified into six groups based on conserved sequence compared with human, Arabidopsis, maize, rice, wheat, tomato, barley, and grape. All homologs of were tissue-specific; most were highly expressed in leaves. ALKBH9B and ALKBH10B are mA demethylases and overexpression of their homologs and reduced mA RNA methylation in transgenic lines. The number of adventitious roots and the biomass accumulation of transgenic lines decreased compared with WT. Therefore, and mediate mA RNA demethylation and play a regulatory role in poplar growth and development. Overexpression of and can reduce the accumulation of HO and oxidative damage by increasing the activities of SOD, POD, and CAT, and enhancing protection for Chl a/b, thereby increasing the salt tolerance of transgenic lines. However, overexpression lines were more sensitive to drought stress due to reduced proline content. This research revealed comprehensive information about the gene family and their roles in growth and development and responsing to salt stress of poplar.
AlkB同源物（）基因家族调控N - 甲基腺苷（mA）RNA甲基化，并参与植物生长和非生物胁迫响应。杨树是研究多年生木本植物的重要模式植物。杨树通常有7 - 10年的较长幼年期，研究开花或成熟木材特性需要很长时间。因此，对杨树物种中该基因的功能研究受到限制。基于与的序列相似性，在杨树84K杂种基因型（×变种）的基因组中鉴定出23个，并且在同源物之间确认了基因结构和保守结构域。与人类、拟南芥、玉米、水稻、小麦、番茄、大麦和葡萄相比，PagALKBH蛋白根据保守序列被分为六组。所有的同源物都具有组织特异性；大多数在叶片中高表达。ALKBH9B和ALKBH10B是mA去甲基化酶，其同源物和在转基因系中的过表达降低了mA RNA甲基化。与野生型相比，转基因系的不定根数量和生物量积累减少。因此，和介导mA RNA去甲基化，并在杨树生长发育中起调控作用。和的过表达可以通过提高超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）的活性，增强对叶绿素a/b的保护，从而减少HO的积累和氧化损伤，进而提高转基因系的耐盐性。然而，由于脯氨酸含量降低，过表达系对干旱胁迫更敏感。本研究揭示了有关该基因家族及其在杨树生长发育和盐胁迫响应中作用的全面信息。
