Plant Molecular Biology

, Volume 74, Issue 4, pp 503–518

Molecular characterization and functional analysis of Glycine max sterol methyl transferase 2 genes involved in plant membrane sterol biosynthesis

  • Anjanasree K. Neelakandan
  • Hanh T. M. Nguyen
  • Rajesh Kumar
  • Lam-Son Phan Tran
  • Satish K. Guttikonda
  • Truyen Ngoc Quach
  • Donovan L. Aldrich
  • W. David Nes
  • Henry T. Nguyen
Article

DOI: 10.1007/s11103-010-9692-6

Cite this article as:
Neelakandan, A.K., Nguyen, H.T.M., Kumar, R. et al. Plant Mol Biol (2010) 74: 503. doi:10.1007/s11103-010-9692-6

Abstract

Sterol C24 methyltransferase (SMT2) genes governing the pattern of phytosterols synthesized in higher plants have been studied in Glycine seedlings and wild-type and engineered Arabidopsis thaliana plants. The SMT2 genes of soybean (SMT2-1 and SMT2-2) previously cloned and characterized (Neelakandan et al. 2009) were shown to complement the SMT deficient cvp1 mutant Arabidopsis plants, consistent with their role in regulation of 24-alkyl sterol-controlled plant physiology. Further analysis of these genes showed that environmental cues, including dehydration, cold, and abscisic acid induced differential changes in transcript levels of the SMT2 during soybean seedling growth. Sterol analyses of transgenic Arabidopsis seeds originating in variant constructs of AtHMGR1, GmSMT1, and GmSMT2 engineered in seeds showed relevant modifications in the ratio of 24-methyl to 24-ethyl sterol in the direction of sitosterol formation. To provide insight into the structural features of the sterol gene that affects transcript regulation, the upstream promoter sequences of soybean SMT2 genes were cloned and characterized. Sequence analysis revealed several important cis-elements and transcription factor binding sites. The analysis of promoter-GUS fusions in transgenic Arabidopsis plants revealed shared and distinct expression features in different developmental stages and tissues. The data are interpreted to imply that SMT2 is an important contributor to normal plant growth and development.

Keywords

Sterol 24-C-methyltransferaseSitosterolCampesterolPromoterCis-elementsGene expressionDevelopmentMutant complementationRegulation

Abbreviations

SMT

Sterol 24-C-methyltransferase

PCR

Polymerase chain reaction

GC-FID

Gas-chromatography-flame ionization detector

BR

Brassinosteroids

SAM

S-Adenosyl methionine

cvp

Cotyledon vascular pattern

HMGR

3-Hydroxy, 3-methylglutaryl coenzyme A reductase

GUS

Beta glucuronidase

2,4-D

2,4-Dichlorophenoxy acetic acid

ABA

Abscisic acid

START

Steroidogenic acute regulatory protein (StAR)-related lipid transfer domain

Supplementary material

11103_2010_9692_MOESM1_ESM.doc (118 kb)
Supplementary material 1 (DOC 117 kb)
11103_2010_9692_MOESM2_ESM.doc (55 kb)
Supplementary material 2 (DOC 55 kb)
11103_2010_9692_MOESM3_ESM.doc (47 kb)
Supplementary material 3 (DOC 47 kb)
11103_2010_9692_MOESM4_ESM.doc (32 kb)
Supplementary material 4 (DOC 31 kb)

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • Anjanasree K. Neelakandan
    • 1
  • Hanh T. M. Nguyen
    • 1
    • 3
  • Rajesh Kumar
    • 1
    • 4
  • Lam-Son Phan Tran
    • 1
    • 5
  • Satish K. Guttikonda
    • 1
    • 6
  • Truyen Ngoc Quach
    • 1
  • Donovan L. Aldrich
    • 1
    • 7
  • W. David Nes
    • 2
  • Henry T. Nguyen
    • 1
  1. 1.Division of Plant Sciences and National Center for Soybean BiotechnologyUniversity of MissouriColumbiaUSA
  2. 2.Department of Chemistry and BiochemistryTexas Tech UniversityLubbockUSA
  3. 3.Center for Plant Science Innovation, Department of Agronomy & HorticultureUniversity of NebraskaLincolnUSA
  4. 4.National Research Center on DNA FingerprintingNational Bureau of Plant Genetic ResourcesNew DelhiIndia
  5. 5.Signaling Pathway Unit, Gene Discovery GroupRIKEN Plant Science CenterYokohamaJapan
  6. 6.Dow AgroSciences LLCIndianapolisUSA
  7. 7.School of ManagementUniversity of Texas at DallasRichardsonUSA