This Article Full Text Full Text (PDF) All Versions of this Article: 133/1/319    most recent pp.102.018309v1 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 Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Wang, D. Articles by Luthe, D. S. Search for Related Content PubMed PubMed Citation Articles by Wang, D. Articles by Luthe, D. S. Agricola Articles by Wang, D. Articles by Luthe, D. S.

ENVIRONMENTAL STRESS AND ADAPTATION

Heat Sensitivity in a Bentgrass Variant. Failure to Accumulate a Chloroplast Heat Shock Protein Isoform Implicated in Heat Tolerance¹

Department of Biochemistry and Molecular Biology, Mississippi State University, Mississippi State, Mississippi 39762

Two variants of creeping bentgrass (Agrostis stolonifera cv palustris), developed using tissue culture, have been used to determine the roles of chloroplast-localized small heat shock proteins (CP-sHSPs) in heat tolerance. Results from previous research indicate that the heat-tolerant variant expressed two additional CP-sHSP isoforms not expressed in the heat-sensitive variant, that accumulation of the additional CP-sHSP isoforms was genetically linked to thermotolerance, and that the presence of the additional isoforms in the heat-tolerant variant provided greater protection to photosystem II during heat stress. To determine the basis of the differential expression, we isolated the genes encoding the CP-sHSPs from both variants and characterized their structure and expression. Two genes, ApHsp26.2 and ApHsp26.7a, were isolated from the heat-tolerant variant, and three genes, ApHsp26.2m, ApHsp26.8, and ApHsp26.7b, were isolated from the heat-sensitive variant. The sequence of ApHsp26.2m from the heat-sensitive variant was identical to ApHsp26.2, except for a point mutation that generated a premature stop codon. Therefore, the protein product of ApHsp26.2m did not accumulate in the heat-sensitive line. Mass spectrometry analysis confirmed that ApHsp26.2 encoded for the CP-sHSP isoforms unique to the heat-tolerant variant. An identical mutation was detected in one of the three parental lines used to develop the creeping bentgrass variants. This suggests that ApHsp26.2m was inherited from this parent and did not arise from a mutation that occurred during tissue culture. The presence of two isoforms encoded by the same gene might be due to differential processing of the N-terminal amino acids during or after import into the chloroplast.

^* Corresponding author; e-mail dsluthe{at}ra.msstate.edu; fax 662-325-8664.

Received November 25, 2002; returned for revision February 5, 2003; accepted May 15, 2003.

This article has been cited by other articles:

				X. Zhang, K. Wang, and E. H. Ervin Optimizing Dosages of Seaweed Extract-Based Cytokinins and Zeatin Riboside for Improving Creeping Bentgrass Heat Tolerance Crop Sci., December 30, 2009; 50(1): 316 - 320. [Abstract] [Full Text] [PDF]

				P.-H. Su and H.-m. Li Arabidopsis Stromal 70-kD Heat Shock Proteins Are Essential for Plant Development and Important for Thermotolerance of Germinating Seeds Plant Physiology, March 1, 2008; 146(3): 1231 - 1241. [Abstract] [Full Text] [PDF]

				I. Neta-Sharir, T. Isaacson, S. Lurie, and D. Weiss Dual Role for Tomato Heat Shock Protein 21: Protecting Photosystem II from Oxidative Stress and Promoting Color Changes during Fruit Maturation PLANT CELL, June 1, 2005; 17(6): 1829 - 1838. [Abstract] [Full Text] [PDF]