Analysis of the potential biological role of LaMYC7 against P. syringae. A, P. syringae infection of WT, 2300, and LaMYC7-overexpressing transgenic lines for 5 days for phenotypic analysis. B, C, Bacterial populations at day 5 in WT, 2300, and LaMYC7-overexpressing transgenic lines (#2, #9). D, E, Antibacterial activity of linalool and caryophyllene against Pst DC3000. LB, empty lysogeny broth; Pst DC3000, 150 μl Pst DC3000 dissolved in lysogeny broth medium; Lin + Pst DC3000, 150 μl Pst DC3000 dissolved in lysogeny broth medium containing 18 μl∙ml.−1 Car + Pst DC3000, 150 μl Pst DC3000 was dissolved in lysogeny broth medium containing 18 μl∙ml−1 Caryophyllene. Numbers shown are the average of at least three replicates (mean ± SD). ANOVA followed by Fisher’s LSD test revealed that the bars labeled with different letters were significantly different (P < 0.05). This can be seen from the vertical lines indicating the standard error at the top of each bar. Credits: Horticultural Research (2024). DOI: 10.1093/times/uhae044
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Analysis of the potential biological role of LaMYC7 against P. syringae. A, P. syringae infection of WT, 2300, and LaMYC7-overexpressing transgenic lines for 5 days for phenotypic analysis. B, C, Bacterial populations at day 5 in WT, 2300, and LaMYC7-overexpressing transgenic lines (#2, #9). D, E, Antibacterial activity of linalool and caryophyllene against Pst DC3000. LB, empty lysogeny broth; Pst DC3000, 150 μl Pst DC3000 dissolved in lysogeny broth medium; Lin + Pst DC3000, 150 μl Pst DC3000 dissolved in lysogeny broth medium containing 18 μl∙ml.−1 Car + Pst DC3000, 150 μl Pst DC3000 was dissolved in lysogeny broth medium containing 18 μl∙ml−1 Caryophyllene. Numbers shown are the average of at least three replicates (mean ± SD). ANOVA followed by Fisher’s LSD test revealed that the bars labeled with different letters were significantly different (P < 0.05). This can be seen from the vertical lines indicating the standard error at the top of each bar. Credits: Horticultural Research (2024). DOI: 10.1093/times/uhae044
Plants face a variety of environmental pressures, including biotic stressors such as pathogens and abiotic stressors such as extreme temperatures. Among biotic stressors, Pseudomonas syringae is a significant threat to plant health worldwide.
Terpenoids such as linalool and caryophyllene play important roles in plant defense mechanisms against such stress factors. However, the transcriptional regulation of these compounds is still poorly understood. These challenges necessitate detailed studies into the regulatory mechanisms underlying terpenoid biosynthesis.
Researchers from the State Key Laboratory of Plant Diversity and Speciality Crops, Chinese Academy of Sciences Horticultural Research.
This study revealed that the lavender LaMYC7 transcription factor significantly promoted the biosynthesis of linalool and caryophyllene, enhancing plant resistance to Pseudomonas syringae. This finding not only sheds light on the transcriptional control of terpenoid biosynthesis, but also suggests potential applications for the development of disease-resistant lavender varieties.
In this study, we used RNA sequencing, recombinant gene technology, and enzyme assays to investigate the role of LaMYC7 in lavender. The results showed that LaMYC7 is highly expressed in glandular trichomes and responds to stresses including UV, low temperature, salinity, drought, methyl jasmonate, and Pseudomonas syringae infection.
Overexpression of LaMYC7 in Nicotiana increases the contents of linalool and caryophyllene and promotes terpenoid biosynthesis. LaMYC7 directly binds to the LaTPS76 promoter and promotes caryophyllene production. Furthermore, linalool exhibited potent antibacterial activity against Pseudomonas syringae. These results suggest that LaMYC7 is essential for plant defense, controls terpenoid biosynthesis, and enhances pathogen resistance.
“Our findings provide valuable insights into the transcriptional regulation of terpenoid biosynthesis in lavender,” said Dr. Lei Shi, corresponding author of the study.
“The identification of LaMYC7 as a key regulator opens new possibilities for breeding lavender varieties with improved disease resistance and higher essential oil yields. This study highlights the importance of understanding plant defense mechanisms at a molecular level in order to develop sustainable agricultural practices.”
The impact of this research is significant, with potential applications in agriculture and the fragrance industry: by manipulating the LaMYC7 gene, breeders could develop lavender varieties with higher yields of valuable essential oils and improved disease resistance, contributing to sustainable crop production and opening up new avenues for lavender’s use in a variety of commercial products.
For more information:
Yanmei Dong et al., LaMYC7, a positive regulator of linalool and caryophyllene biosynthesis, confers resistance to plants against Pseudomonas syringae, Horticultural Research (2024). DOI: 10.1093/times/uhae044
Journal Information:
Horticultural Research
