Stable expression of AtGA2ox1 in a low-input turfgrass (Paspalum notatum Flugge) reduces bioactive gibberellin levels and improves turf quality under field conditions

Mrinalini Agharkar, Paula Lomba, Fredy Altpeter, Hangning Zhang, Kevin Kenworthy, Theo Lange

Research output: Contribution to journalArticlepeer-review

72 Scopus citations


Bahiagrass (Paspalum notatum Flugge) is a prime candidate for molecular improvement of turf quality. Its persistence and low input characteristics made it the dominant utility turfgrass along highways in the south-eastern USA. However, the comparatively poor turf quality due to reduced turf density and prolific production of unsightly inflorescences currently limits the widespread use of bahiagrass as residential turf. Alteration of endogenous gibberellin (GA) levels by application of growth regulators or transgenic strategies has modified plant architecture in several crops. GA catabolizing AtGA2ox1 was subcloned under the control of the constitutive maize ubiquitin promoter and Nos 3'UTR. A minimal AtGA2ox1 expression cassette lacking vector backbone sequences was stably introduced into apomictic bahiagrass by biolistic gene transfer as confirmed by Southern blot analysis. Expression of AtGA2ox1 in bahiagrass as indicated by reverse transcription-polymerase chain reaction and Northern blot analysis resulted in a significant reduction of endogenous bioactive GA 1 levels compared to wild type. Interestingly, transgenic plants displayed an increased number of vegetative tillers which correlated with the level of AtGA2ox1 expression and enhanced turf density under field conditions. This indicates that GAs contribute to signalling the outgrowth of axillary buds in this perennial grass. Transgenic plants also showed decreased stem length and delayed flowering under controlled environment and field conditions. Consequently, turf quality following weekly mowing was improved in transgenic bahiagrass. Transgene expression and phenotype were transmitted to seed progeny. Argentine bahiagrass produces seeds asexually by apomixis, which reduces the risk of unintended transgene dispersal by pollen and results in uniform progeny.

Original languageEnglish (US)
Pages (from-to)791-801
Number of pages11
JournalPlant Biotechnology Journal
Issue number6
StatePublished - Nov 1 2007
Externally publishedYes


  • Bahiagrass
  • Biolistic gene transfer
  • Gibberellin 2-oxidase
  • Plant architecture
  • Transgenic turfgrass
  • Turf quality

ASJC Scopus subject areas

  • Biotechnology
  • Agronomy and Crop Science
  • Plant Science


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