Embracing the complexity of plant-microbe-insect interactions under a changing climate for sustainable agriculture

Tripartite interactions of an endophytic entomopathogenic fungus, Asian corn borer, and host maize under elevated carbon dioxide

BACKGROUND

Biological control of insect pests is encountering an unprecedented challenge in agricultural systems due to the ongoing rise in carbon dioxide (CO2) level. The use of entomopathogenic fungi (EPF) in these systems is gaining increased attention, and EPF as crop endophytes hold the potential for combining insect pest control and yield enhancement of crops, but the effects of increased CO2 concentration on this interaction are poorly understood. Here, the introduction of endophytic EPF was explored as an alternative sustainable management strategy benefiting crops under elevated CO2, using maize (Zea mays), Asian corn borer (Ostrinia furnacalis), and EPF (Beauveria bassiana) to test changes in damage to maize plants from O. furnacalis, and the nutritional status (content of carbon, nitrogen, phosphorus, potassium), biomass, and yield of maize.

RESULTS

The results showed that endophytic B. bassiana could alleviate the damage caused by O. furnacalis larvae for maize plants under ambient CO2 concentration, and this effect was enhanced under higher CO2 concentration. Inoculation with B. bassiana effectively counteracted the adverse impact of elevated CO2 on maize plants by preserving the nitrogen content at its baseline level (comparable with ambient CO2 conditions without B. bassiana). Both simultaneous effects could explain the improvement of biomass and yield of maize under B. bassiana inoculation and elevated CO2.

CONCLUSION

This finding provides key information about the multifaceted benefits of B. bassiana as a maize endophyte. Our results highlight the promising potential of incorporating EPF as endophytes into integrated pest management strategies, particularly under elevated CO2 concentrations. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Alternative certification system for supply chain sustainability: how stakeholder alignment affects institutionalization

Purpose

This study expands the isomorphic logic on the participatory guarantee system (PGS) alternative certification method, which aims to level the supply chain sustainability field to determine how the alignment of disadvantaged agrifood stakeholders (e.g. small/applicant farmers, local organizations, consumers and volunteer auditors) might neutralize the negative effects of stakeholder heterogeneity (SH) on PGS recognition.

Design/methodology/approach

The sample comprised 113 multilateral matching questionnaires collected from disadvantaged agrifood stakeholders participating in the PGS activities of the Green Conservation Label managed by Taiwan's Tse-Xin Organic Agriculture Foundation (TOAF). This study adopted hierarchical regression to test the hypotheses.

Findings

Stakeholder alignment, external community (EC) constructs, similar backgrounds (SBs) and value congruence (VC) diminish the negative effects of SH on PGS recognition.

Social implications

PGS is an agrifood supply chain social movement designed to allow underprivileged actors to enact solutions collectively to address social inequities and ecological problems through fair procedures, collective assignments and collaborative intentionality. PGS members who leverage VC, SB and EC will have a greater chance of successfully overcoming their institutional disadvantages.

Originality/value

Based on the PGS activities initiated by disadvantaged agrifood stakeholders, this study transformed isomorphic logics, including coercive, mimetic and normative isomorphisms, into a mechanism with which individuals can build a governance structure that helps disadvantaged agrifood stakeholders develop alternative institutions by pooling their resources.

Unconventional routes to developing insect-resistant crops

Concerns over widespread use of insecticides and heightened insect pest virulence under climate change continue to fuel the need for environmentally safe and sustainable control strategies. However, to develop such strategies, a better understanding of the molecular basis of plant-pest interactions is still needed. Despite decades of research investigating plant-insect interactions, few examples exist where underlying molecular mechanisms are well characterized, and even rarer are cases where this knowledge has been successfully applied to manage harmful agricultural pests. Consequently, the field appears to be static, urgently needing shifts in approaches to identify novel mechanisms by which insects colonize plants and plants avoid insect pressure. In this perspective, we outline necessary steps for advancing holistic methodologies that capture complex plant-insect molecular interactions. We highlight novel and underexploited approaches in plant-insect interaction research as essential routes to translate knowledge of underlying molecular mechanisms into durable pest control strategies, including embracing microbial partnerships, identifying what makes a plant an unsuitable host, capitalizing on tolerance of insect damage, and learning from cases where crop domestication and agronomic practices enhance pest virulence.