Author
Yang, Litao | |
Lin, Hong | |
TAKAHASHI, YURI - University Of California | |
CHEN, FENG - University Of Tennessee | |
WALKER, M.A. - University Of California | |
Civerolo, Edwin |
Submitted to: Physiological and Molecular Plant Pathology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/3/2010 Publication Date: 1/31/2011 Citation: Yang, L., Lin, H., Takahashi, Y., Chen, F., Walker, M., Civerolo, E.L. 2011. Proteomic analysis of grapevine tissues in response to Xylella fastidiosa infection. Physiological and Molecular Plant Pathology. 75(3):90-99. Interpretive Summary: Xylella fastidiosa (Xf) is the pathogenic bacterium which causes Pierce’s disease (PD), as well as numerous economically important agronomic, horticultural and ornamental plant diseases. In this study, a pair of PD resistant (9621-67) and susceptible (9621-94) grapevines from a cross of Vitis rupestris x V. arizonica were selected for protein expression analyses. Using protein extraction, separation and identification techniques, five V. vinifera proteins and five homologous proteins were identified by their differential expression levels at different tissues and developmental stages in Xf-free and Xf-infected genotypes. Among them, a thaumatin-like protein and the pathogenesis-related protein 10 from both genotypes, and the 40S ribosomal protein S25 from the susceptible genotype were found to be up-regulated in response to Xf-infection. Three heat shock proteins, 17.9 kDa class II, protein 18 and 21 were up-regulated only in control group. However, a down-regulated putative ripening related protein was found in the Xf-infected susceptible genotype. A putative GTP-binding protein was also found to be down-regulated in the susceptible genotype. Our results revealed that differential expression of proteins in response to Xf-infection was genotype and tissue development stage dependent. The specific roles of these candidate proteins in alleviation or aggravation of this disease are under investigation. The information obtained in this study will aid in the understanding the mechanisms related to the host-pathogen interactions involved in PD, and for developing sustainable PD management strategies. Technical Abstract: Xylella fastidiosa (Xf) is the bacterial causal agent of Pierce’s disease (PD) as well as other economically important diseases in a number of agronomic, horticultural and ornamental plants. The objective of this research was to identify candidate proteins that are differentially expressed in grapevines and involved in disease development or defense responses to Xf infection. To achieve this goal a comparative proteomic analysis to characterize differentially expressed protein profiles from Xf infected grape tissue was undertaken. A pair of siblings from a cross of Vitis rupestris x V. arizonica, 9621-67 (highly susceptible) and 9621-94 (highly resistant), were selected for this study. Total proteins were isolated from the shoots of uninoculated controls and Xf- infected plants at 1, 6, and 12 weeks after inoculation, separated by a 2D-PAGE system, and spots representing differentially expressed proteins were processed and detected using LC/MS/MS. Protein identification was performed using BLAST and NCBI protein databases. Five V. vinifera proteins and five homologous proteins were identified by their differential expression at different tissue developmental stages in these infected genotypes. A thaumatin-like protein and the pathogenesis-related protein 10 from both genotypes, and the 40S ribosomal protein S25 from the susceptible genotype were found to be up-regulated in response to Xf-infection. Furthermore, the expression of the thaumatin-like protein increased sharply 12 weeks post-inoculation in resistant genotypes only. Three heat shock proteins, 17.9 kDa class II, protein 18 and 21 were highly expressed in healthy tissues compared with those in tisses infected with Xf, and heat shock protein 21 was not detectable in the Xf-infected susceptible genotype. In addition, a down-regulated putative ripening related protein was found in the Xf-infected susceptible genotype. Glycoprotein and formate dehydrogenase were identified in the resistant genotype and their expression was constant during plant development. A putative GTP-binding protein was down-regulated in the susceptible genotype. Our results revealed that differential expression of proteins in response to Xf-infection was genotype and tissue development stage dependent. The specific roles of these candidate proteins in alleviation or aggravation of this disease are under investigation. The information obtained in this study will aid in the understanding of the mechanisms related to the host-pathogen interactions involved in PD. |