Characterization of the Heat Shock Response in Cultured Sugarcane Cells

Abstract

Effect of heat shock on the growth of cultured sugarcane cells (Saccharum officinarum L.) was measured. Heat shock (HS) treatment at 36 to 380C (2 hours) induced the development of maximum thermotolerance to otherwise nonpermissive heat stress at 540C (7 minutes). Optimum thermotolerance was observed 8 hours after heat shock. Development of thermotolerance was initiated by treatments as short as 30 minutes at 360C. Temperatures below 360C or above 400C failed to induce maximum thermotolerance. In vivo labeling revealed that HS at 32 to 340C induced several high molecular mass heat shock proteins (HSPs). A complex of 18 kilodalton HSPs required at least 360C treatment for induction. The majority of the HSPs began to accumulate within 10 minutes, whereas the synthesis of low molecular mass peptides in the 18 kilodalton range became evident 30 minutes after initiation of HS. HS above 380C resulted in progressively decreased HSP synthesis with inhibition first observed for HSPs larger than 50 kilodaltons. Analysis of two-dimensional gels revealed a complex pattern of label incorporation including the synthesis of four major HSPs in the 18 kilodalton range and continued synthesis of constitutive proteins during HS.The mechanism by which biological organisms respond to elevated temperature, the HSR,2 has been shown to be highly conserved at the genetic level in both prokaryotes and eukaryotes. Moderately elevated temperature leads to selective transcription and translation resulting in specific proteins that are termed HSPs as well as the development of tolerance to otherwise lethal high temperature stress (see ref. 21 for a recent review). The HSR of higher plants is similar to that of other organisms. The HSPs have been characterized in great detail in soybean (10,16,17,20), maize (4, 9), tobacco (11,15), and tomato (25).

Violaxanthin De-Epoxidase (Purification of a 43-Kilodalton Lumenal Protein from Lettuce by Lipid-Affinity Precipitation with Monogalactosyldiacylglyceride)

“…Two-dimensional IEF/SDS-PAGE was also run using minigels according to the method of Moisyadi and Harrington (1989) with an ampholyte range between pH 4.5 and 6.5. Gels were stained with Coomassie brilliant blue R-250.…”

Sugarcane proteomics: Establishment of a protein extraction method for 2‐DE in stalk tissues and initiation of sugarcane proteome reference map

“…This method is commonly used for plant protein extraction to eliminate the interfering substances during sample preparation. In sugarcane, only phenol and SDS methods were used so far, to extract proteins 13–17 . Since sugarcane tissues are rich in carbohydrates and contain less amount of protein, 100 mg of the dried pellet was used for extraction with 1 mL of LB.…”

“…Different protein extraction methods have been used for 2‐DE analysis in many plants (for reviews see 7, 8–11), however, only the phenol‐SDS protein extraction method was followed in sugarcane. In sugarcane, most of the research articles published so far emphasized protein extraction from leaf tissues alone 13–17. To our knowledge, there is no report on sugarcane stalk proteome analysis.…”

“…Hitherto, none of these studies has utilized high‐throughput proteomic approach to either generate inventory of expressed proteins or to develop a 2‐D gel reference map. Nevertheless, these studies have provided useful information on expressed proteins in sugarcane 13–17. We are interested in studying the stalk tissues, primarily due to the fact that stalk as a representative tissue sample is pertinent in case studies involving host–pathogen interaction, especially for studying the red rot of sugarcane, a devastating disease.…”

Two-step Heat Treatment of Pineapple Crowns Increases Thermotolerance

“…In the HSR a moderate heat shock treatment induces thermotolerance to subsequent higher temperature treatments. Heat shock protein (HSP) is a component of the HSR and has been linked to thermotolerance in wheat, soybean, and sugarcane (Hendershot et al, 1992, Krishnan et al, 1989Moisyadi andBarrington, 1989, Shuster et al, 1988). HSP production can be induced by exposing plants or cell suspensions to temperatures 8-10C above normal growing conditions for 30 min to 2 h. Maximum HSP synthesis generally occurs after a 2-h treatment (Hendershot et al, 1992;Moisyadi and Barrington, 1989;Kimple and Key, 1985).…”