Work

Age versus stage: does ontogeny modify the effect of phosphorus and arbuscular mycorrhizas on above‐ and below‐ground defence in forage sorghum?

Year: 2013

Type: article

Abstract: Arbuscular mycorrhizas (AM) can increase plant acquisition of P and N. No published studies have investigated the impact of P and AM on the allocation of N to the plant defence, cyanogenic glucosides. We investigated the effects of soil P and AM on cyanogenic glucoside (dhurrin) concentration in roots and shoots of two forage sorghum lines differing in cyanogenic potential (HCNp). Two harvest times allowed plants grown at high and low P to be compared at the same age and the same size, to take account of known ontogenetic changes in shoot HCNp. P responses were dependent on ontogeny and tissue type. At the same age, P-limited plants were smaller and had higher shoot HCNp but lower root HCNp. Ontogenetically controlled comparisons showed a P effect of lesser magnitude, and that there was also an increase in the allocation of N to dhurrin in shoots of P-limited plants. Colonization by AM had little effect on shoot HCNp, but increased root HCNp and the allocation of N to dhurrin in roots. Divergent responses of roots and shoots to P, AM and with ontogeny demonstrate the importance of broadening the predominantly foliar focus of plant defence studies/theory, and of ontogenetically controlled comparisons.

Source: Plant Cell & Environment

DOI: 10.1111/pce.12209

Authors: REBECCA E. MILLER, ROSLYN M. GLEADOW, TIMOTHY R. CAVAGNARO

Institutions: The University of Melbourne, Monash University, The University of Adelaide

Language: English

Topic: Mycorrhizal Fungi and Plant Interactions

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: bronze

Funders: Monash University, Directorate for Biological Sciences