Involvement of Deg5 protease in wounding-related disposal of PsbF apoprotein

• Published in: Plant physiology and biochemistry Vol. 49; no. 3; pp. 311 - 320
• Main Authors: Luciński, Robert, Misztal, Lucyna, Samardakiewicz, Sławomir, Jackowski, Grzegorz
• Format: Journal Article
• Language: English
• Published: Paris Elsevier Masson SAS 01-03-2011; Elsevier
• Subjects: Adaptation, Physiological - genetics; Apoproteins - metabolism; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Biological and medical sciences; Chloroplast; Chloroplasts - ultrastructure; Darkness; Deg protease; DNA, Bacterial; Fundamental and applied biological sciences. Psychology; Mutagenesis, Insertional; Phenotype; Photosystem II Protein Complex - metabolism; Plant Diseases - genetics; Plant Leaves - anatomy & histology; Plant Leaves - metabolism; Plant physiology and development; PsbF; Serine Endopeptidases - genetics; Serine Endopeptidases - metabolism; Starch - metabolism; Stress, Physiological - genetics; Wounding; Arabidopsis thaliana; PsbF; Wounding; SDS-PAGE; Deg protease; Chl; PSII; Chloroplast; Enzyme; Injury; Peptidases; Plant physiology; Cruciferae; Apoproteins; Dicotyledones; Angiospermae; Hydrolases; Spermatophyta; Experimental plant
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2011.01.001

Deg5 is a serine-type protease peripherally attached to luminal side of thylakoid membrane. Given the lack of knowledge concerning its function homozygous T-DNA insertion line depleted in Deg5 was prepared to study the functional importance of this protease in
Arabidopsis thaliana.
deg5 mutants displayed a pleiotropic phenotype with regard to fourth whorl leaves of four-weeks old plants. The alterations involved an increased leaf area, reduced leaf thickness, reduced cross-sectional area of palisade mesophyll cells as well as changed chloroplast ultrastructure including lack of signs of entering the senescence phase (e.g. presence of much smaller plastoglobules) and the accumulation of large starch grains at the end of the dark period. It was shown that whereas PsbA, C and F apoproteins of photosystem II reaction center undergo an extensive disappearance in response to a set of brief stresses
deg5 mutant was fully resistant to the disappearance of PsbF apoprotein which follows an exposition of leaves to wounding. Our results demonstrate that Deg5 is of seminal importance for normal plant development and degradation of PsbF which occurs following brief wounding.
► PsbA, C and F apoproteins undergo a disappearance in response to four brief stresses. ► Deg5 is responsible for wounding-related disposal of PsbF apoprotein. ►
deg5 mutant displays changes in leaf morphology, anatomy and chloroplast ultrastructure.