A key feature of innate immunity is the ability to recognize and respond to potential pathogens in a highly sensitive and specific manner. In plants, the first layer of defense is induced after recognition by pattern recognition receptors of microbe-associated molecular patterns. This recognition elicits a defense program known as pattern-triggered immunity. Pathogen entry into host tissue is a critical early step in causing infection. For foliar bacterial pathogens, natural surface openings such as stomata, are important entry sites. Stomata in contact with bacteria rapidly close and can thus restrict bacterial entry into leaves. The molecular mechanisms regulating stomatal closure upon pathogen perception are not yet well-understood. Plant lectin receptor kinases are thought to play crucial roles during development and in the adaptive response to various stresses. Although the function of most plant lectin receptor kinases is still not clear, a role for this kinase family in plant innate immunity is emerging. Here, we summarize recent progresses in the identification of lectin receptor kinases involved in plant innate immunity. We also discuss the role of lectin receptor kinases in stomatal innate immunity signaling.
One of the biggest demanding situations for food security in the 21st century is to enhance crop yield stability through the improvement of diseases-resistant crops. Managing plant health is a major challenge for modern food production and compounded by the lack of common ground among the many disease control disciplines involved. All plants simultaneously engage with billions of microbes which can be collectively referred to as the plant microbiome. Most microbes inside the plant microbiome are harmless or even beneficial to the plant as they promote plant growth or provide protection in opposition to diseases. However, some of these microbes also cause disease with devastating effects on crop yields. To prevent pathogen infection, plants have evolved an advanced innate immune system that recognizes conserved cell surface molecules that most pathogen possesses. Activation of the plant immune system stops the invading pathogen, however this comes with fitness cost that significantly reduces plant growth and leads to yield penalty. Apart from their innate immune system controlling pre-programmed defense reactions, plants can also increase the responsiveness of their immune system in response to selected environmental signals. This phenomenon is known as “defense priming”. Although defense priming rarely provides full protection, its broad-spectrum effectiveness, low-fitness cost, long‐lasting durability and inherited to future generations make it attractive for sustainable crop protection.