Fu Chunlin, Bian Chunyang, Chen Jing, Zhang Qian, Qin Dong, Li Jiangkuo, Zhang Peng, Huo Junwei, Gang Huixin
Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Northeast Region), Ministry of Agriculture and Rural Affairs, College of Horticulture & Landscape Architecture, Northeast Agricultural University, Harbin, 150030, China; National-Local Joint Engineering Research Center for Development and Utilization of Small Fruits in Cold Regions, Northeast Agricultural University, Harbin, 150030, China.
Institute of Agricultural Products Preservation and Processing Technology, Tianjin Academy of Agricultural Sciences, Tianjin, 300384, China; Tianjin Key Laboratory of Postharvest Physiology and Storage of Agricultural Products, National Engineering and Technology Research Center for Preservation of Agricultural Products, Tianjin, 300384, China.
J Plant Physiol. 2025 Jan;304:154409. doi: 10.1016/j.jplph.2024.154409. Epub 2024 Dec 14.
MYB transcription factors exert crucial functions in enhancing plant stress tolerance, which is impacted by soil drought and salinity. In our study, the R2R3-type MYB transcription factor gene LcMYB5 from blue honeysuckle (Lonicera caerulea L.) was successfully cloned and identified, and confirmed its nuclear localization. LcMYB5 overexpression was vastly enhanced drought and salt tolerance in both blue honeysuckle and tobacco seedlings. After drought stress, transgenic tobacco exhibited an average survival rate of 70.30%, while most wild-type (WT) plants perished, resulting in a survival rate of only 15.33%. Following salt stress, the average survival rate for transgenic tobacco reached 77.24%, compared to just 22.47% for WT plants. Measurements indicated, that transgenic tobacco had higher proline content than WT, as well as higher superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activity. Transgenic tobacco decreased chlorophyll content less dramatically than WT tobacco, despite both tobaccos having decreased chlorophyll content. Furthermore, the level of malondialdehyde (MDA) and relative conductivity were lower in transgenic tobacco compared to WT. Furthermore, LcMYB5 overexpression significantly increased the expression levels of key genes related to drought stress (NCED1, NCED2, PYL4, PYL8, and CBL1) and salt stress (NHX1, SOD, CAT1, SOS1, and HSP17.8), thus improving transgenic tobacco's stress tolerance. Compared to WT blue honeysuckle, transiently transformed LcMYB5-expressing blue honeysuckle exhibited milder damage under stress conditions, a significant increase in chlorophyll and proline content was observed, the activities of SOD, POD and CAT were also significantly increased, the increase in MDA content and relative conductivity is relatively small. Additionally, In addition, transient expression of LcMYB5 can also positively regulate the expression of these five key genes of drought stress and five key genes of salt stress, so as to improve the resistance of transgenic blue honeysuckle to drought and salt stress. In summary, our study reveals the important regulatory role of LcMYB5 in plant resistance to drought and salt stress, providing theoretical support and potential application value for further improving crop stress resistance.
MYB转录因子在增强植物抗逆性方面发挥着关键作用，而植物抗逆性受到土壤干旱和盐度的影响。在我们的研究中，成功克隆并鉴定了来自蓝靛果忍冬（Lonicera caerulea L.）的R2R3型MYB转录因子基因LcMYB5，并证实了其核定位。LcMYB5的过表达极大地增强了蓝靛果忍冬和烟草幼苗的耐旱性和耐盐性。干旱胁迫后，转基因烟草的平均存活率为70.30%，而大多数野生型（WT）植株死亡，存活率仅为15.33%。盐胁迫后，转基因烟草的平均存活率达到77.24%，而WT植株仅为22.47%。测量结果表明，转基因烟草的脯氨酸含量高于WT，超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性也更高。尽管两种烟草的叶绿素含量均有所下降，但转基因烟草叶绿素含量的下降幅度小于WT烟草。此外，转基因烟草中丙二醛（MDA）水平和相对电导率低于WT。此外，LcMYB5的过表达显著提高了与干旱胁迫相关的关键基因（NCED1、NCED2、PYL4、PYL8和CBL1）和盐胁迫相关的关键基因（NHX1、SOD、CAT1、SOS1和HSP17.8）的表达水平，从而提高了转基因烟草的抗逆性。与WT蓝靛果忍冬相比，瞬时表达LcMYB5的蓝靛果忍冬在胁迫条件下损伤较轻，叶绿素和脯氨酸含量显著增加，SOD、POD和CAT活性也显著增加，MDA含量和相对电导率的增加相对较小。此外，LcMYB5的瞬时表达还可以正向调节这五个干旱胁迫关键基因和五个盐胁迫关键基因的表达，从而提高转基因蓝靛果忍冬对干旱和盐胁迫的抗性。综上所述，我们的研究揭示了LcMYB5在植物抗旱和耐盐胁迫中的重要调控作用，为进一步提高作物抗逆性提供了理论支持和潜在应用价值。
