Plants take the splice to the fight

Abstract

Signal Transduction Plants transiently activate immune responses using layers of diverse regulatory mechanisms. This strategy minimizes any potential damage from an overly active protective response. Dressano et al. discovered in the model plant Arabidopsis that when an immune response was activated, the plant's immunoregulatory RNA binding protein (IRR) became dephosphorylated. Dephosphorylation altered IRR's interaction with messenger RNA transcripts, including that of calcium-dependent protein kinase 28 (CPK28), a key negative regulator of pattern recognition receptor signaling complexes. CPK28 is acutely regulated by changes in calcium concentration and its own phosphorylation state. However, altered splicing results in the expression of a truncated CPK28 protein that cannot bind calcium, and thus an enhanced immune response can be triggered. Nat. Plants 6 , 1008 (2020).