The "middle way" of plant defense response: a new mechanism of plants fine-tuning growth-defense balance
If plants reallocate resource to enhance resistance without restriction, growth and development would be arrested, even cause death. This brings us a question: how plants modulate the balance between meeting the necessary growth and achieving maximum resistance? The underlying mechanism remains unclear.
Molecular Plant online published a research article entitled “DELLA and EDS1 Form A Feedback Regulatory Module to Fine-tune Plant Growth-Defense Tradeoff in Arabidopsis”, by HOU Xingliang’s research group in South China Botanical Garden of Chinese Academy of Sciences, reported the latest research progress on the precise regulation of growth-defense balance in plants.
DELLA protein is a key negative regulator of gibberellin (GA) signaling pathway, which functions in many aspects of plant growth and development, and also participates in the regulation of plant stress response. In this study, it was found that DELLA protein could interact with EDS1, a key plant disease resistance factor, by a yeast two-hybrid screening. In the presence of EDS1, Pst DC3000 and salicylic acid (SA) could antagonize the GA-triggered degradation of DELLA protein, thus suppressing plant growth. DELLA could impair the binding of EDS1 to downstream target promoter to reduce the expression of disease-resistant genes.
regulatory loop in modulating the balance of plant growth and defense against pathogen.
It is well known that plant diseases often cause significant loss of crop yield. Conventional breeding has found that varieties with high resistance to disease are usually accompanied by low yield. To growth, or to defense, that is an important issue. In this study, the DELLA member RGL3 was found to inhibit plant growth only under external stress, thus providing a possible solution to promote plant disease resistance with minor impact on normal growth.