University Of Tasmania

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Impact of defoliation severity on photosynthesis, carbon metabolism and transport gene expression in perennial ryegrass

journal contribution
posted on 2023-05-17, 09:00 authored by Lee, JM, Sathish, B, Donaghy, DJ, Roche, JR
Defoliation severity affects grass regrowth. The changes to biological processes affecting regrowth induced by severe defoliation are not fully understood, nor have they been investigated at a molecular level in field-grown plants. Fieldgrown perennial ryegrass (Lolium perenne L.) plants were defoliated to 20, 40 or 60mmduring winter. Throughout regrowth, transcript profiles of 17 genes involved in photosynthesis and carbon metabolism or transport were characterised in stubble and lamina tissue. Although defoliation to 20mm reduced residual lamina area and stubble water-soluble carbohydrate reserves compared with plants defoliated to 40 or 60 mm,net herbage regrowth was not reduced. Transcript profiles indicated a potential compensatory mechanism that may have facilitated regrowth. At the one-leaf regrowth stage, plants defoliated to 20mm had greater abundance of photosynthesis-related gene transcripts (rca, rbcS1, rbcS2, fba, fbp and fnr) and 20% greater stubble total nitrogen than plants defoliated to 60 mm. A greater capacity for photosynthesis in outer leaf sheaths may be one potential mechanism used by severely defoliated plants to compensate for the reduced residual lamina area; however, this premise requires further investigation.


Publication title

Functional Plant Biology: An International Journal of Plant Function










Tasmanian Institute of Agriculture (TIA)


C S I R O Publishing

Place of publication

150 Oxford St, Po Box 1139, Collingwood, Australia, Victoria, 3066

Rights statement

Copyright © 2011 CSIRO

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  • Restricted

Socio-economic Objectives

Sown pastures (excl. lucerne)

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