Expression of callose synthase genes and its connection with Npr1 signaling pathway during pathogen infection

Abstract

Callose synthesis occurs at specific stages of plant cell wall development in all cell types, and in response to pathogen attack, wounding and physiological stresses. We determined the expression pattern of "upstream regulatory sequence" of 12 Arabidopsis callose synthase genes (CalS1-12) genes and demonstrated that different callose synthases are expressed specifically in different tissues during plant development. That multiple CalS genes are expressed in the same cell type suggests the possibility that CalS complex may be constituted by heteromeric subunits. Five CalS genes were induced by pathogen (Hyaloperonospora arabidopsis, previously known as Peronospora parasitica, the causal agent of downy mildew) or salicylic acid (SA), while the other seven CalS genes were not affected by these treatments. Among the genes that are induced, CalS1 and CalS12 showed the highest responses. In Arabidopsis npr1 mutant, impaired in response of pathogenesis related (PR) genes to SA, the induction of CalS1 and CalS12 genes by the SA or pathogen treatments was significantly reduced. The patterns of expression of the other three CalS genes were not changed significantly in the npr1 mutant. These results suggest that the high induction observed of CalS1 and CalS12 is Npr1 dependent while the weak induction of five CalS genes is Npr1 independent. In a T-DNA knockout mutant of CalS12, callose encasement around the haustoria on the infected leaves was reduced and the mutant was found to be more resistant to downy mildew as compared to the wild type plants.

The Coiled-Coil and Nucleotide Binding Domains of BROWN PLANTHOPPER RESISTANCE14 Function in Signaling and Resistance against Planthopper in Rice

“…Further studies will be needed to determine whether RLCK281 is involved in regulating SA signaling. Additionally, studies on phytohormone defense signaling have shown that SA treatment can affect callose synthase gene expression (Jacobs et al, 2003;Dong et al, 2008). We propose that LOC_Os01g67364.1 may function as part of a callose synthase and contribute to callose accumulation to protect plants against BPH attack.…”

Transient expression of the <i>Arabidopsis thaliana</i> callose synthase PMR4 increases penetration resistance to powdery mildew in barley

“…In Arabidopsis thaliana, 12 callose synthase genes are described [4]. They showed a tissue-specific expression [6], which was also reported from callose synthase genes in wheat [7]. Among the 12 callose synthases in A. thaliana, PMR4 (POWDERY MILDEW RESITANT 4, also called GLU-CAN SYNTHASE LIKE 5) is responsible for woundand pathogen-induced callose formation [8,9].…”

Callose Synthase GSL7 Is Necessary for Normal Phloem Transport and Inflorescence Growth in Arabidopsis

“…Callose is synthesized from the sugar nucleotide UDPglucose via callose synthases that span the plasma membrane. In both vascular and nonvascular plants, callose synthases are encoded by multigene families, and different isoforms have different locations and functions in the plant (Voigt et al, 2006;Dong et al, 2008;Schober et al, 2009;Schuette et al, 2009). Of the 12 Glucan Synthase-Like (GSL; also called CalS) genes in Arabidopsis (Arabidopsis thaliana), five are suggested or proven from mutational and correlative analyses to encode isoforms with important functions in pollen development (GSL1, GSL2, GSL5, GSL8, and GSL10; Enns et al, 2005;Nishikawa et al, 2005;Tö ller et al, 2008;Huang et al, 2009).…”

“…Of the 12 Glucan Synthase-Like (GSL; also called CalS) genes in Arabidopsis (Arabidopsis thaliana), five are suggested or proven from mutational and correlative analyses to encode isoforms with important functions in pollen development (GSL1, GSL2, GSL5, GSL8, and GSL10; Enns et al, 2005;Nishikawa et al, 2005;Tö ller et al, 2008;Huang et al, 2009). Two genes have been implicated in cytokinesis, cell plate formation, and cell patterning (GSL6 and GSL8; Hong et al, 2001;Chen et al, 2009;Thiele et al, 2009) and one in response to attack by fungal pathogens (GSL5; Jacobs et al, 2003;Nishimura et al, 2003;Dong et al, 2008). Expression of the GSL6 gene is elevated and callose is deposited locally in response to phloem feeding by silverleaf whitefly nymphs (Bemisia sp.…”