Peter Wolf

Correction: Quantum biology and ultraweak photon emission: an overlooked intersection?

Frontiers Production Office

Plastoquinone’s pivotal role in photosynthesis and redox sensing: a thylakoid redox hub for chloroplast and cyanobacterial signaling

Sapna Tiwari, Rinkesh Gupta, Anjali Gupta, Priyul Pandey, Shailendra Pratap Singh

Photosynthesis is the fundamental light-driven process where photoautotrophs convert carbon dioxide into sugars. The necessary reducing power is generated by the Photosynthetic Electron Transport Chain (PETC), which takes place in the thylakoid membrane. The mobile electron carrier Plastoquinone (PQ) is central to this process. The PQ reduction-oxidation cycle is not only the rate-limiting step of photosynthesis but also a key control point for PETC activity. Beyond its role in electron transport, PQ acts as a crucial redox sensor, initiating gene expression pathways related to photosynthesis and environmental stress. Furthermore, the redox state of PQ governs distinct non-photosynthetic functions; non-photoreducible PQ serves as a stress-response reservoir in plants and algae, while photoreducible PQ helps to regulate circadian rhythm in cyanobacteria. These diverse roles underscore PQ’s pivotal importance in sensing the external light environment and enabling photoprotection. This review examines the various roles of PQ in cyanobacteria, algae, and higher plants, extending beyond its well-established function in photosynthesis. Additionally, we will discuss how controlling the redox state of PQ can be strategically applied for biomanufacturing purposes, including its potential in Biophotovoltaics (BPV) technology for generating photocurrent.

Quantum biology and ultraweak photon emission: an overlooked intersection?

Betony Adams, Adriana Marais, Tjaart P. J. Krüger, Francesco Petruccione

Biophotons–or ultraweak photon emissions (UPE) – remain a peripheral research subject compared to conventional topics in quantum biology such as photosynthesis, avian magnetoreception, and olfaction, despite significant intersections between the fields. Re-examining UPE research through the lens of quantum biology may help address confounding questions around these light-matter interactions. One principal argument against a biologically functional role for UPE is the extremely low intensity. However, as quantum biology expands to consider non-linear optical phenomena, effects such as superradiance are attracting growing interest. These collective light–matter interactions could provide mechanisms through which initially weak photon signals become enhanced within organisms, increasing their effective biological impact. If such processes occur in living systems, they may help explain how ultraweak emissions participate in cellular communication and regulation, challenging the view that biophotons are merely incidental metabolic by-products. Another canonical topic in quantum biology is the radical pair mechanism, most famously used as a model to explain the avian compass, and more recently, applied to the production and balance of reactive oxygen species (ROS). The oxidative metabolic and stress-response processes that generate ROS are also implicated in the production of UPE. This would suggest a fruitful overlap of spin chemistry with UPE research and open a line of investigation as to whether magnetic field effects mediated through radical pairs have any influence on UPE production. In this short Perspective paper we will expand on these intersections between two fields that have had surprisingly little conversation between them.

Sexual dimorphism and pattern of resource allocation under variable abiotic factors

Yash Mangla

Dioecious taxa partition resources between sexes to fulfil maternal and paternal functions. The biased partitioning of resources results in differences in morphological, physiological, and life-history traits between sexes, thereby giving rise to sexual dimorphism. Such a pattern enables the evolution and maintenance of dioecy. The interaction between abiotic factors and sex-specific allocation strongly influences the extent of sexual dimorphism and shapes sex-specific adaptive strategies. These strategies enable the survival of the species in given ecological contexts. The key life-history traits associated with dioecy are also strongly influenced by abiotic factors and are intrinsically connected to evolutionary pathways. In dioecious taxa, both sexes exhibit plasticity in resource allocation, enabling them to survive. Under optimal light and water conditions, sex-specific responses may not appear, but at various stress levels male and female plants often differ in photosynthetic efficiency, stress tolerance, and growth patterns. Research indicates that the extent of this specialization is limited and far from a unifying generalization. Nonetheless, it could be argued that the higher reproductive cost may lead to a reduction in stress tolerance in females. Moreover, higher water use efficiency allows males to better survive in xeric conditions. Thus, the poor reproductive, vegetative, and physiological performance of females has been observed under stress conditions. The combined effect of multiple stresses may be much more pronounced than of each acting independently. This may also change the magnitude of physiological specialization between sexes. These factors modulate life history traits such as the spatial segregation of sexes, clonality etc. among dioecious taxa and, as a result, may enhance the extent of sexual dimorphism. Intriguingly, generalizations made at present may not hold true for the future due to plasticity responses exhibited by dioecious plants that have been investigated, so the generalization remains context-dependent.

Giovanni Venturoli: The career of a real scholar

Bruno Andrea Melandri