This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 147/4/2147    most recent pp.108.123810v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Shoresh, M. Articles by Harman, G. E. Search for Related Content PubMed PubMed Citation Articles by Shoresh, M. Articles by Harman, G. E. Agricola Articles by Shoresh, M. Articles by Harman, G. E.

PLANTS INTERACTING WITH OTHER ORGANISMS

The Molecular Basis of Shoot Responses of Maize Seedlings to Trichoderma harzianum T22 Inoculation of the Root: A Proteomic Approach^1,[W]

Department of Horticultural Sciences, Cornell University, Geneva, New York 14456

Trichoderma spp. are effective biocontrol agents for several soil-borne plant pathogens, and some are also known for their abilities to enhance systemic resistance to plant diseases and overall plant growth. Root colonization with Trichoderma harzianum Rifai strain 22 (T22) induces large changes in the proteome of shoots of maize (Zea mays) seedlings, even though T22 is present only on roots. We chose a proteomic approach to analyze those changes and identify pathways and genes that are involved in these processes. We used two-dimensional gel electrophoresis to identify proteins that are differentially expressed in response to colonization of maize plants with T22. Up- or down-regulated spots were subjected to tryptic digestion followed by identification using matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry and nanospray ion-trap tandem mass spectrometry. We identified 91 out of 114 up-regulated and 30 out of 50 down-regulated proteins in the shoots. Classification of these revealed that a large portion of the up-regulated proteins are involved in carbohydrate metabolism and some were photosynthesis or stress related. Increased photosynthesis should have resulted in increased starch accumulation in seedlings and did indeed occur. In addition, numerous proteins induced in response to Trichoderma were those involved in stress and defense responses. Other processes that were up-regulated were amino acid metabolism, cell wall metabolism, and genetic information processing. Conversely, while the proteins involved in the pathways noted above were generally up-regulated, proteins involved in other processes such as secondary metabolism and protein biosynthesis were generally not affected. Up-regulation of carbohydrate metabolism and resistance responses may correspond to the enhanced growth response and induced resistance, respectively, conferred by the Trichoderma inoculation.

The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Michal Shoresh (michalsho{at}volcani.agri.gov.il).

^[W] The online version of this article contains Web-only data.

www.plantphysiol.org/cgi/doi/10.1104/pp.108.123810

^* Corresponding author; e-mail michalsho{at}volcani.agri.gov.il.

Received May 31, 2008; accepted June 10, 2008; published June 18, 2008.