An Arabidopsis Callose Synthase, GSL5, Is Required for Wound and Papillary Callose Formation.
Arabidopsis was transformed with double-stranded RNA interference (dsRNAi) constructs designed to silence three putative callose synthase genes: GLUCAN SYNTHASE-LIKE5 (GSL5), GSL6, and GSL11. Both wound callose and papillary callose were absent in lines transformed with GSL5 dsRNAi and in a corresponding sequence-indexed GSL5 T-DNA insertion line but were unaffected in GSL6 and GSL11 dsRNAi lines. These data provide strong genetic evidence that the GSL genes of higher plants encode proteins that are essential for callose formation. Deposition of callosic plugs, or papillae, at sites of fungal penetration is a widely recognized early response of host plants to microbial attack and has been implicated in impeding entry of the fungus. Depletion of callose from papillae in gsl5 plants marginally enhanced the penetration of the grass powdery mildew fungus Blumeria graminis on the nonhost Arabidopsis. Paradoxically, the absence of callose in papillae or haustorial complexes correlated with the effective growth cessation of several normally virulent powdery mildew species and of Peronospora parasitica.
Jacobs
Andrew K
AK
Australian Centre for Plant Functional Genomics, University of Adelaide, Waite Campus, Glen Osmond, South Australia 5064, Australia.
Lipka
Volker
V
Burton
Rachel A
RA
Panstruga
Ralph
R
Strizhov
Nicolai
N
Schulze-Lefert
Paul
P
Fincher
Geoffrey B
GB
D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D056229:Fungal Structures / Q000254:growth & development; D005658:Fungi / Q000254:growth & development; D005936:Glucans / Q000096:biosynthesis*; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism*; D007113:Immunity, Innate / Q000235:genetics / Q000502:physiology; D008565:Membrane Proteins; D009154:Mutation; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000382:microbiology; D030821:Plants, Genetically Modified; D034622:RNA Interference / Q000502:physiology; D012330:RNA, Double-Stranded / Q000235:genetics / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D013314:Stress, Mechanical
D004269:DNA, Bacterial; D005936:Glucans; D008565:Membrane Proteins; D012330:RNA, Double-Stranded; D029702:Schizosaccharomyces pombe Proteins; C036483:T-DNA; C048306:callose; D005964:Glucosyltransferases; C020570:1,3-beta-glucan synthase