Key Laboratory of Agricultural Biotechnology of Liaoning Province, College of Biosciences and Biotechnology, Shenyang Agricultural University, Shenyang, China.
Plant Cell Rep. 2024 Oct 6;43(11):253. doi: 10.1007/s00299-024-03333-5.
CRISPR/Cas9-mediated knockout of SlWOX4 gene in tomato enhances tolerance to drought stress. Drought stress is one of the major abiotic factors that seriously affects plant growth and crop yield. WUSCHEL-related homeobox (WOX) transcription factors are involved in plant growth, development and stress response. However, little is known about the role of WOX genes in drought tolerance in tomato. Here, SlWOX4, a member of the WOX family in tomato, was functionally characterized in mediating drought tolerance. SlWOX4 was homologous to Nicotiana tabacum NtWOX4 with a conserved HD domain, and was localized in the nucleus. SlWOX4 was significantly down-regulated by drought and abscisic acid (ABA) treatments. The loss-of-function mutations of SlWOX4 produced using the CRISPR-Cas9 system in tomato improved drought tolerance by reducing water loss rate and enhancing stomatal closure. In addition, the wox4 lines exhibited reduced accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA), increased antioxidant enzyme activity, proline contents and ABA contents under drought stress. Moreover, gene editing of SlWOX4 in tomato enhanced drought tolerance by regulating the expression of genes encoding antioxidants and ABA signaling molecules. In summary, SlWOX4 gene might negatively regulate drought stress tolerance in tomato and has great potential as a drought-resistant crop-breeding target genes.
CRISPR/Cas9 介导的番茄 SlWOX4 基因敲除增强了耐旱性。干旱胁迫是严重影响植物生长和作物产量的主要非生物因素之一。WUSCHEL 相关同源盒（WOX）转录因子参与植物的生长、发育和应激反应。然而，关于 WOX 基因在番茄耐旱性中的作用知之甚少。本研究中，番茄 WOX 家族的成员 SlWOX4 被鉴定为参与介导耐旱性。SlWOX4 与烟草 NtWOX4 同源，具有保守的 HD 结构域，定位于细胞核中。干旱和脱落酸（ABA）处理显著下调 SlWOX4 的表达。使用 CRISPR-Cas9 系统在番茄中产生的 SlWOX4 功能丧失突变，通过降低水分流失率和增强气孔关闭来提高耐旱性。此外，wox4 系在干旱胁迫下表现出活性氧（ROS）和丙二醛（MDA）积累减少、抗氧化酶活性、脯氨酸含量和 ABA 含量增加。此外，番茄 SlWOX4 的基因编辑通过调节抗氧化剂和 ABA 信号分子编码基因的表达增强了耐旱性。总之，SlWOX4 基因可能负调控番茄的耐旱性，作为抗旱作物育种的靶基因具有很大的潜力。
