Symbiotic interactions as drivers of trade - offs in plants effects of fungal endophytes on tall fescue

Studying the controls on biomass allocation trade-offs in plants are important since they affect harvestable product yields and are critical to understanding symbiotic interactions. Epichloae fungal endophytes associate with cool-season grasses, growing systemically within the plant inter-cellular spaces and are transmitted through seeds. We explore the endophytes influence on the relationship between the plant reproductive and vegetative aboveground biomass [reproductive effort: RE] and on the trade-off between two components of the reproductive biomass, number and weight of panicles [RPN], using tall fescue as a model system. Naturally endophyte-colonized, manipulatively endophyte-free, and naturally endophyte-free plants from Northern European wild-populations together with the cultivar Kentucky-31 were grown under different environmental conditions [nutrients x water]. The endophyte had an effect on the RPN [E+: 6.19, ME-: 4.68 and E-: 4.40] which indicates how reproductive biomass is partitioned into number and mass of panicles, but not on RE [approximately equal to 0.06]. As expected, wild plants showed higher reproductive effort [approximately equal to 0.06] compared to the cultivar KY-31 [0.05], irrespective of endophyte presence. Endophyte-colonized plants had lighter panicles than endophyte-free plants, a pattern that was clear among low-yielding plants. Similarly, the trade-off between RPN and RE was higher for endophyte-colonized plants. This was again evident among plants with low RE indicating that colonized plants split the yield into either greater number of panicles and/or lighter panicles. The effect of vertically transmitted endophytes has earlier been studied as ratios [e.g. RE]; however, our study shows that this approach may hide size-dependent endophyte effects on these relationships. Our study reveals that Neotyphodium endophyte affects trade-offs in tall fescue plants in a complex manner, and is influenced by a number of biological and abiotic factors.

Bibliographic Details

Main Authors:	Gundel, Pedro Emilio, Garibaldi, Lucas Alejandro, Helander, Marjo, Saikkonen, Kari
Format:	Texto biblioteca
Language:	eng
Subjects:	ALLOMETRY, BIOMASS PARTITIONING, FESTUCA, NEOTYPHODIUM, PLANT-ENDOPHYTE INTERACTION, SYMBIOSIS, FESTUCA ARUNDINACEA, POACEAE,
Online Access:	http://ceiba.agro.uba.ar/cgi-bin/koha/opac-detail.pl?biblionumber=46947
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