C4 crops such as maize and sorghum are vital to global food and bioenergy systems due to their high productivity and resource use efficiency, underpinned by a CO2 concentrating mechanism. Despite this advantage, modelling and experimental evidence indicate that C4 photosynthesis can be further optimised to boost yield and carbon capture. This review examines key metabolic and physiological processes predicted to limit C4 photosynthetic flux by the steady-state and dynamic models, including the activity of carboxylases, electron transport, and mesophyll and bundle sheath (BS) conductance. We highlight recent progress using Setaria viridis and model crops to test genetic strategies for alleviating these limitations. In addition, we explore promising but less-understood areas, such as enhancing light-harvesting and adenosine triphosphate (ATP) generation in BS cells, improving metabolite exchange and activating alternative decarboxylation pathways under stress. We suggest that improving C4 photosynthesis will require coordinated manipulation of multiple biochemical and regulatory processes. Advancing our understanding of these processes will not only enhance C4 crop productivity and resilience but also support long-term goals of engineering C4 traits into C3 crops to address rising demands for food, energy, and climate adaptation.
This review discusses the use of agronomic management practices to enhance crop stress resilience to climate stress through the modulation of natural plant growth regulatory pathways. The use of biostimulants or plant hormones to improve crop resilience is subject to strict regulatory oversight if changes in the regulation of plant growth are implied. Climate change is a major threat to crop potential and is characterized by both long-term shifts in temperature and precipitation patterns as well as increased occurrence of extreme weather events, posing an immediate threat to agriculture. Breeding and exogenous inputs have been used to enhance cropping system resilience, although these management practices are either too slow or constrained by cost and availability, to address rapidly emerging climate challenges. Exogenous biostimulants, microbials and plant hormones have shown great promise as novel mechanisms to optimize natural plant resilience, resulting in immediate but non-permanent improvements in plant responses to climate-induced stresses, representing a powerful but underexplored approach to enhance crop productivity under climate stress. The use of these exogenous inputs is, however, constrained by outdated and scientifically unsound regulations that consider any such modification as pesticidal in nature. The failure to modernize regulatory frameworks for the use of biostimulants in agriculture will constrain the development of safe effective tools and deprive growers of means to respond to climate change. Here, we discuss the scientific rationale for eliminating the regulatory barriers governing biostimulants or products that modulate plant regulatory networks and propose a framework for enabling legislation to strengthen cropping system resilience.
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：