Tea plants glowing with protective energy, symbolizing enhanced plant immunity.

Tea's Secret Weapon: How This Compound Boosts Plant Immunity

Author's portrait.
Nico Varela in Science & Nature July 2025 • 4 min read.

"Discover how benzothiadiazole (BTH) enhances disease resistance in tea plants, offering a sustainable solution for crop protection."


Tea, derived from Camellia sinensis, is a globally cherished beverage, cultivated across more than 35 countries. Its widespread appeal stems not only from its aromatic qualities but also from its health-promoting compounds, including antioxidants like epigallocatechin and catechin. These compounds contribute to overall well-being and help plants resist various pathogens.

However, tea plants are vulnerable to numerous diseases, significantly impacting both the quality and quantity of tea production. Among these, Diplodia disease, caused by Lasiodiplodia theobromae, poses a substantial threat, particularly in the sub-Himalayan regions of West Bengal, India. This disease can affect tea plants at any stage of development, making effective management strategies essential.

In response to biotic and abiotic stresses, plants have developed sophisticated defense mechanisms. One key process involves phenylpropanoids, which act as precursors to vital secondary metabolites. The induction of systemic acquired resistance (SAR) involves salicylic acid, regulated by phenylalanine ammonia-lyase (PAL) gene expression, playing a crucial role in bolstering plant immunity. This study investigates how benzothiadiazole (BTH), can enhance tea plant resistance against L. theobromae by inducing PAL gene expression.

Benzothiadiazole: Enhancing Tea Plant Immunity

Tea plants glowing with protective energy, symbolizing enhanced plant immunity.

The research focused on twelve-month-old tea seedlings (TV-26) treated with benzothiadiazole (BTH) and then inoculated with Lasiodiplodia theobromae. Transcript accumulation was measured in treated-uninoculated, untreated-inoculated, and treated-inoculated plants, compared against untreated-uninoculated controls, to evaluate BTH's impact on defense induction. Key findings revealed that BTH significantly enhances tea plant immunity, making it a potential tool for sustainable agriculture.

Results indicated that BTH-treated and L. theobromae-inoculated plants exhibited higher transcript accumulation (3.81 µg/µl) and a reduced disease index (3.8 ± 0.02) compared to the untreated control, which had a transcript accumulation of 3.26 µg/µl and a disease index of 14.6 ± 0.05. These results confirm BTH's effectiveness in boosting the plant's defense mechanisms.

  • Higher Transcript Accumulation: Plants treated with BTH and inoculated with L. theobromae showed a significant increase in transcript accumulation.
  • Reduced Disease Index: The disease index was notably lower in BTH-treated plants compared to untreated controls, indicating enhanced resistance.
  • Gene Sequencing: Sequencing, nucleotide, and deduced protein sequences were compared, and the 3D structure was established, revealing three lyase superfamily motifs (cl26059).
  • Increased PAL Activity: Treated-inoculated plants showed a marked increase in PAL activity from 2.5 to 4.4 µmol min−1 g−1 compared to healthy controls (2.5 to 2.7 µmol min−1 g−1) after the fourth day of treatment.
Further analysis involved sequencing, nucleotide, and deduced protein sequences, leading to the establishment of a 3D structure that identified three lyase superfamily (cl26059) motifs. Additionally, PAL activity was observed to increase in treated-inoculated plants, rising from 2.5 to 4.4 µmol min−1 g−1 after the 4th day of treatment, compared to healthy controls, which remained at 2.5 to 2.7 µmol min−1 g−1. These molecular insights underscore the biochemical mechanisms through which BTH enhances plant defense.

Future Implications

Benzothiadiazole emerges as a significant inducer of PAL, offering a promising avenue for enhancing disease resistance in tea plants. By leveraging BTH, tea growers can potentially reduce reliance on traditional pesticides, fostering more sustainable and environmentally friendly agricultural practices. Future research could explore optimal application methods and long-term effects, paving the way for broader adoption in tea cultivation and other crops.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

Everything You Need To Know

1

What is benzothiadiazole (BTH) and how does it help tea plants?

Benzothiadiazole (BTH) is a compound that enhances the disease resistance in tea plants. It works by inducing phenylalanine ammonia-lyase (PAL) gene expression. This process boosts the plant's defense mechanisms, making it more resistant to pathogens like Lasiodiplodia theobromae, the cause of Diplodia disease.

2

How does Lasiodiplodia theobromae affect tea plants and why is it a problem?

Lasiodiplodia theobromae causes Diplodia disease in tea plants, which can affect the plants at any stage of development. This poses a significant threat to tea production, impacting both the quality and quantity of tea. The disease is particularly problematic in regions like the sub-Himalayan areas of West Bengal, India.

3

Can you explain the role of phenylalanine ammonia-lyase (PAL) in tea plant defense?

Phenylalanine ammonia-lyase (PAL) is a key enzyme involved in the defense mechanisms of tea plants. It plays a crucial role in systemic acquired resistance (SAR). When induced by benzothiadiazole (BTH), PAL helps to fortify the plant's immunity against pathogens. PAL activity increases, leading to higher levels of defense compounds, which helps the tea plants resist disease.

4

What were the key findings of the research on benzothiadiazole (BTH) and tea plants?

The research revealed that benzothiadiazole (BTH) significantly enhances tea plant immunity against Lasiodiplodia theobromae. The key findings include higher transcript accumulation in plants treated with BTH and inoculated with L. theobromae, a reduced disease index in BTH-treated plants compared to untreated controls, and a marked increase in PAL activity in treated-inoculated plants. These results confirm BTH's effectiveness in boosting the plant's defense mechanisms, offering a sustainable solution for crop protection.

5

What are the potential benefits of using benzothiadiazole (BTH) in tea cultivation, and what future research is needed?

Benzothiadiazole (BTH) offers a promising path for enhancing disease resistance in tea plants, potentially reducing the need for traditional pesticides. By using BTH, tea growers can move towards more sustainable and environmentally friendly agricultural practices. Future research should explore optimal application methods and the long-term effects of BTH. Further investigation into its effectiveness on other crops could broaden its use in agriculture, promoting wider adoption and furthering sustainable farming.

Newsletter Subscribe

Subscribe to get the latest articles and insights directly in your inbox.