Our Paper of the Month January is 'Plasticity of seed weight compensates reductions in seed number of oilseed rape in response to shading at flowering' and our paper of the Month February is 'Dynamic plant–plant–herbivore interactions govern plant growth–defence integration'.
Paper of the Month February 2017
Dynamic plant–plant–herbivore interactions govern plant growth–defence
Plants downregulate their defences against insect herbivores upon impending competition for light. This has long been considered a resource trade-off, but recent advances in plant physiology and ecology suggest this mechanism is more complex. Here we propose that to understand why plants regulate and balance growth and defence, the complex dynamics in plant–plant competition and plant–herbivore interactions needs to be considered. Induced growth–defence responses affect plant competition and herbivore colonisation in space and time, which has consequences for the adaptive value of these responses. Assessing these complex interactions strongly benefits from advanced modelling tools that can model multitrophic interactions in space and time. Such an exercise will allow a critical re-evaluation why and how plants integrate defence and competition for light.
Jorad de Vries, Jochem B. Evers, and Erik H. Poelman (2017) Trends in Plant Science (online first 13 January 2017)
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Paper of the Month January 2017
Plasticity of seed weight compensates reductions in seed number of
oilseed rape in response to shading at flowering
Understanding the response of the number of seeds and seed weight to the availability of assimilates is crucial for designing breeding strategies aimed to increase seed and oil yield in oilseed rape. This study aims to answer the questions: i) do seed number and seed weight in oilseed rape differ in their plasticity in response to the availability of assimilates at flowering? and ii) how sensitive are oil and protein concentrations to the availability of assimilates during flowering?
A spring oilseed rape hybrid was sown in two field experiments and the treatments were combinations of i) two plant densities and ii) shading or no shading between the beginning and end of flowering. Seed yield was not affected by plant density or by shading. Lower plant density was compensated by an increase in seed number per plant, without effects on single-seed weight. However, the negative effect of shading during flowering on seed number per area was fully compensated by an increase in single-seed weight by 47–61%. The plasticity of single-seed weight observed in the present study of oilseed rape has never been reported for annual seed crops. Shading at flowering increased both the seed filling rate and the duration of the seed filling period at all positions in the canopy. We also observed that the reduction of the source-sink ratio at flowering increasing seed weight does not necessarily modify oil or protein concentrations. Thus, single-seed weight could be targeted to increase seed yield in oilseed rape without compromising oil content.
Marcelo H. Labra, Paul C. Struik, Jochem B. Evers, Daniel F. Calderini (2017) European Journal of Agronomy 84: 113-124
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