+ Site Statistics
References:
54,258,434
Abstracts:
29,560,870
PMIDs:
28,072,757
+ Search Articles
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ PDF Full Text
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Translate
+ Recently Requested

Overexpression of Brassica juncea wild-type and mutant HMG-CoA synthase 1 in Arabidopsis up-regulates genes in sterol biosynthesis and enhances sterol production and stress tolerance



Overexpression of Brassica juncea wild-type and mutant HMG-CoA synthase 1 in Arabidopsis up-regulates genes in sterol biosynthesis and enhances sterol production and stress tolerance



Plant Biotechnology Journal 10(1): 31-42



Brassica juncea 3-hydroxy-3-methylglutaryl-CoA synthase (HMGS) is encoded by four isogenes (BjHMGS1-BjHMGS4). In vitro enzyme assays had indicated that the recombinant BjHMGS1 H188N mutant lacked substrate inhibition by acetoacetyl-CoA (AcAc-CoA) and showed 8-fold decreased enzyme activity. The S359A mutant demonstrated 10-fold higher activity, while the H188N/S359A double mutant displayed a 10-fold increased enzyme activity and lacked inhibition by AcAc-CoA. Here, wild-type and mutant BjHMGS1 were overexpressed in Arabidopsis to examine their effects in planta. The expression of selected genes in isoprenoid biosynthesis, isoprenoid content, seed germination and stress tolerance was analysed in HMGS overexpressors (OEs). Those mRNAs encoding enzymes 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), sterol methyltransferase 2 (SMT2), delta-24 sterol reductase (DWF1), C-22 sterol desaturase (CYP710A1) and brassinosteroid-6-oxidase 2 (BR6OX2) were up-regulated in HMGS-OEs. The total sterol content in leaves and seedlings of OE-wtBjHMGS1, OE-S359A and OE-H188N/S359A was significantly higher than OE-H188N. HMGS-OE seeds germinated earlier than wild-type and vector-transformed controls. HMGS-OEs further displayed reduced hydrogen peroxide (H(2) O(2) )-induced cell death and constitutive expression of salicylic acid (SA)-dependent pathogenesis-related genes (PR1, PR2 and PR5), resulting in an increased resistance to Botrytis cinerea, with OE-S359A showing the highest and OE-H188N the lowest tolerance. These results suggest that overexpression of HMGS up-regulates HMGR, SMT2, DWF1, CYP710A1 and BR6OX2, leading to enhanced sterol content and stress tolerance in Arabidopsis.

(PDF emailed within 0-6 h: $19.90)

Accession: 054818579

Download citation: RISBibTeXText

PMID: 21645203

DOI: 10.1111/j.1467-7652.2011.00631.x


Related references

Overexpression of spermidine synthase enhances tolerance to multiple environmental stresses and up-regulates the expression of various stress-regulated genes in transgenic Arabidopsis thaliana. Plant & Cell Physiology 45(6): 712-722, 2004

Effect of morpholine-like fungicides on growth and sterol composition of a wild-type strain and a sterol mutant of Ustilago maydis defective in sterol D-8 fwdarw -DELTA-7 isomerase activity. THE BRITISH CROP PROTECTION COUNCIL [Author] Brighton Crop Protection Conference: Pests and Diseases, Vols 1, 2 and 3 : 3) 215-220, 1992

An Arabidopsis mutant deficient in sterol biosynthesis: heterologous complementation by ERG 3 encoding a delta 7-sterol-C-5-desaturase from yeast. Plant Journal 8(3): 407-416, 1995

Effect of morpholine-like fungicides on growth and sterol composition of a wild-type strain and a sterol mutant of Ustilago maydis defective in sterol Delta 8-> Delta 7 isomerase activity. Brighton Crop Protection Conference, Pests and Diseases 1992 Volume 1: 215-220, 1992

Sterol esterification is mediated by two genes in yeast and regulates sterol biosynthesis. Circulation 92(8 SUPPL ): I496, 1995

Long-term effects of sterol depletion in C. elegans: sterol content of synchronized wild-type and mutant populations. Journal of Lipid Research 45(11): 2044-2051, 2004

Expression of Arabidopsis phytochelatin synthase in Indian mustard (Brassica juncea) plants enhances tolerance for Cd and Zn. Planta 225(5): 1277-1285, 2006

Overexpression of Arabidopsis Phytochelatin Synthase (AtPCS1) in Indian mustard (Brassica juncea) shows partial enhancement for Cd tolerance. In Vitro Cellular and Developmental Biology-Animal 40: 47A-47A, 2004

Virus-induced gene silencing of Withania somnifera squalene synthase negatively regulates sterol and defence-related genes resulting in reduced withanolides and biotic stress tolerance. Plant Biotechnology Journal 13(9): 1287-1299, 2016

Brassica juncea 3-hydroxy-3-methylglutaryl (HMG)-CoA synthase 1: expression and characterization of recombinant wild-type and mutant enzymes. Biochemical Journal 383(Pt. 3): 517-527, 2004

Plant sterol metabolism. Δ(7)-Sterol-C5-desaturase (STE1/DWARF7), Δ(5,7)-sterol-Δ(7)-reductase (DWARF5) and Δ(24)-sterol-Δ(24)-reductase (DIMINUTO/DWARF1) show multiple subcellular localizations in Arabidopsis thaliana (Heynh) L. Plos One 8(2): E56429, 2013

Multiple DNA elements for sterol regulatory element-binding protein and NF-Y are responsible for sterol-regulated transcription of the genes for human 3-hydroxy-3-methylglutaryl coenzyme A synthase and squalene synthase. Journal of Biochemistry 123(6): 1191-1198, 1998

Overexpression of multiple dehydrin genes enhances tolerance to freezing stress in Arabidopsis. Plant Molecular Biology 54(5): 743-753, 2004

Overexpression of cystathionine-gamma-synthase enhances selenium volatilization in Brassica juncea. Planta 218(1): 71-78, 2003

Overexpression of cotton PYL genes in Arabidopsis enhances the transgenic plant tolerance to drought stress. Plant Physiology and Biochemistry 115: 229-238, 2017