In the complex family of heat stress transcription factors, HsfA1 has a unique role as master regulator of thermotolerance in tomato

  • Mishra S
  • Tripp J
  • Winkelhaus S
 et al. 
  • 156

    Readers

    Mendeley users who have this article in their library.
  • 260

    Citations

    Citations of this article.

Abstract

We generated transgenic tomato plants with altered expression of heat stress transcription factor HsfA1. Plants with 10-fold overexpression of HsfA1 (OE plants) were characterized by a single HsfA1 transgene cassette, whereas plants harboring a tandem inverted repeat of the cassette showed cosuppression (CS plants) by posttranscriptional silencing of the HsfA1 gene connected with formation of small interfering RNAs. Under normal growth conditions, major developmental parameters were similar for wild-type (WT), OE, and CS plants. However, CS plants and fruits were extremely sensitive to elevated temperatures, because heat stress-induced synthesis of chaperones and Hsfs was strongly reduced or lacking. Despite the complexity of the plant Hsf family with at least 17 members in tomato, HsfA1 has a unique function as master regulator for induced thermotolerance. Using transient reporter assays with mesophyll protoplasts from WT tomato, we demonstrated that plasmid-encoded HsfA1 and HsfA2 were well expressed. However, in CS protoplasts the cosuppression phenomenon was faithfully reproduced. Only transformation with HsfA2 expression plasmid led to normal expression of the transcription factor and reporter gene activation, whereas even high amounts of HsfA1 expression plasmids were silenced. Thermotolerance in CS protoplasts was restored by plasmid-borne HsfA2, resulting in expression of chaperones, thermoprotection of firefly luciferase, and assembly of heat stress granules.

Author-supplied keywords

  • Chaperones
  • Heat stress transcription factors
  • Posttranscriptional gene silencing
  • Thermotolerance
  • Tomato
  • siRNA

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

  • Shravan Kumar Mishra

  • Joanna Tripp

  • Sybille Winkelhaus

  • Bettina Tschiersch

  • Klaus Theres

  • Lutz Nover

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free