RNA sequencing maps woodland strawberries' rapid defense mechanisms against gray mold

A study has illuminated how woodland strawberries launch rapid defense mechanisms against Botrytis cinerea, the fungus responsible for devastating gray mold. Using high-resolution RNA sequencing, researchers mapped the strawberry's swift systemic response and the pathogen's persistent gene activity during early infection stages.

These findings, published in the journal Horticulture Research, are key to advancing strategies aimed at enhancing plant immunity, offering promising directions for safeguarding strawberry crops from this widespread disease.

Gray mold, caused by Botrytis cinerea, is a major threat to over 200 plant species, including economically vital crops like strawberries. The disease thrives in wet, humid conditions, leading to severe crop losses. While chemical treatments are commonly used to control the fungus, they are not always effective and pose environmental concerns.

Due to these challenges, there is a growing demand for deeper research into the molecular interactions between B. cinerea and its hosts, with the ultimate goal of improving plant resistance and ensuring greater agricultural resilience.

The study, conducted by researchers at Nanjing Agricultural University, examined the early stages of infection between woodland strawberry (Fragaria vesca) and B. cinerea. By employing dense RNA-seq technology, the team monitored gene expression changes in both the plant and the pathogen during the first 12 hours of infection.

Their findings provide crucial insights into how strawberries initiate early defenses, paving the way for developing gray mold-resistant strawberry varieties.

The research captured interactions between F. vesca and B. cinerea at 14 key points over 12 hours, revealing the rapid activation of the strawberry's immune response soon after infection. The most significant gene activity occurred in the first few hours, where genes related to cell wall reinforcement, defense proteins, and hormone signaling were upregulated.

These early defenses helped prevent the pathogen from establishing itself in plant tissues. B. cinerea displayed sustained genetic activity throughout the infection, employing various strategies to invade the plant, such as secreting enzymes that weaken cell walls and proteins that trigger plant cell death.

One key discovery was the role of the FvRLP2 gene in strawberries, which was found to inhibit fungal infection—a promising target for future breeding of disease-resistant crops.

Dr. Zong-Ming Cheng, the lead researcher at Nanjing Agricultural University, stated, "Our study underscores the intricate nature of plant-pathogen interactions during the initial stages of infection. The early defense mechanisms we observed in Fragaria vesca provide valuable insights into how plants respond to necrotrophic pathogens like Botrytis cinerea.

"These findings open up exciting opportunities for breeding programs focused on strengthening plant resistance by targeting key defense-related genes." He added that these discoveries could significantly reduce the economic impact of gray mold on strawberry production.

The agricultural implications of this research are extensive, particularly for strawberry growers. By identifying critical defense genes, breeders can develop new strawberry cultivars that are more resistant to gray mold, reducing the need for chemical fungicides and minimizing crop losses.

In the future, molecular breeding techniques could provide a sustainable approach to bolstering strawberry crop resilience, ultimately ensuring greater food security.

More information:
Yibo Bai et al, The dynamic arms race during the early invasion of woodland strawberry by Botrytis cinerea revealed by dual dense high-resolution RNA-seq analyses, Horticulture Research (2023). DOI: 10.1093/hr/uhad225

Provided by NanJing Agricultural University