skip to main content

Title: Capsicum annuum homeobox 1 (CaHB1) is a nuclear factor that has roles in plant development, salt tolerance, and pathogen defense

Highlights: •The CaHB1 is a nuclear factor, belonging to HD-Zip proteins. •SA and ET, as signal molecules, modulate CaHB1-mediated responses. •Overexpression of CaHB1 in tomato resulted in a thicker cell wall. •CaHB1-transgenic tomato confers resistance to Phytophthora infestans. •CaHB1 enhanced tolerance to saline stress in tomato. -- Abstract: Homeodomain-leucine zipper (HD-Zip) family proteins are unique to plants, but little is known about their role in defense responses. CaHB1 is a nuclear factor in peppers, belonging to subfamily II of HD-Zip proteins. Here, we determined the role of CaHB1 in the defense response. CaHB1 expression was induced when pepper plants were challenged with Phytophthora capsici, a plant pathogen to which peppers are susceptible, or environmental stresses such as drought and salt stimuli. CaHB1 was also highly expressed in pepper leaves following application of SA, whereas ethephon and MeJA had a moderate effect. To further investigate the function of CaHB1 in plants, we performed gain-of-function study by overexpression of CaHB1 in tomato. CaHB1-transgenic tomatoes showed significant growth enhancement including increased leaf thickness and enlarged cell size (1.8-fold larger than control plants). Microscopic analysis revealed that leaves from CaHB1-transgenic plants had thicker cell walls and cuticle layers than those from controls. Moreover, CaHB1-transgenicmore » plants displayed enhanced resistance against Phytophthora infestans and increased tolerance to salt stress. Additionally, RT-PCR analysis of CaHB1-transgenic tomatoes revealed constitutive up-regulation of multiple genes involved in plant defense and osmotic stress. Therefore, our findings suggest roles for CaHB1 in development, salt stress, and pathogen defense.« less
Authors:
;  [1] ;  [2] ; ;  [3] ;  [1]
  1. Department of Plant Science, College of Agriculture and Life Sciences, Seoul National University, Seou1 151-742 (Korea, Republic of)
  2. Screening Division, Korea Research Institute of Chemical Technology, Daejeon 305-600 (Korea, Republic of)
  3. Korea Research Institute of Bioscience and Biotechnology, Yusung, Daejeon 305-600 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22242225
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemical and Biophysical Research Communications; Journal Volume: 442; Journal Issue: 1-2; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; CAPSICUM; CELL WALL; LEAVES; LEUCINE; PATHOGENS; PEPPERS; POLYMERASE CHAIN REACTION; PROTEINS; SALTS; TOMATOES; TRANSGENIC PLANTS