Plant synthetic biology is a rapidly advancing multidisciplinary research area that applies engineering principles to design, construct, and implement new plant capabilities at the molecular, cellular, and whole organism scales. Synthetic gene circuits are important tools for enabling increased customizability in the control of gene expression in plants, with widespread applications spanning new approaches for basic biology to introduction of new traits for advancing agriculture. In this review, we first aimed to provide a comprehensive understanding of synthetic circuits. Next, we discuss recent progress in the construction of advanced synthetic gene circuits in plants for programmable control of gene expression. Finally, we discuss the current challenges associated with developing and applying effective circuits while also highlighting future prospects and research directions, including quantitative measurement, high-throughput testing, and circuit modelling.

Calcium ions (Ca2+) play pivotal roles in a host of cellular signalling processes. The requirement to maintain resting cytosolic Ca2+ levels in the 100–200 nM range provides a baseline for dynamic excursions from resting levels that determine the nature of many physiological responses to external stimuli and developmental processes. This review provides an overview of the key components of the Ca2+ homeostatic machinery, including known channel-mediated Ca2+ entry pathways along with transporters that act to shape the cytosolic Ca2+ signature. The relative roles of the vacuole and endoplasmic reticulum as sources or sinks for cytosolic Ca2+ are considered, highlighting significant gaps in our understanding. The components contributing to mitochondrial, chloroplast and nuclear Ca2+ homeostasis and organellar Ca2+ signals are also considered. Taken together, a complex picture of the cellular Ca2+ homeostatic machinery emerges with some clear differences from mechanisms operating in many animal cells.

In the current polycrisis era, plant science, particularly when applied to agronomy, becomes instrumental: because our main substantial and renewable resource is plant biomass, many future solutions will depend on our ability to grow and transform plant material in a sustainable way. This also questions the way we conduct plant research and thus quantitative plant biology. In response to the increasing polarization between science and society, participatory plant research offers a pertinent framework. Far from moving away from quantitative approaches, participatory plant research builds on complexity associated with biology and situated knowledge. When researchers and citizens work together on societal issues, such friction becomes more fertile, quantitative questions become more complex, societal issues are addressed at their roots and outcomes often exceed that of top-down strategies. This article serves as an introduction to this ongoing bifurcation in plant science, using plant breeding as a key example.

Phosphorus (P) is a non-renewable resource that limits plant productivity due to its low bioavailability in the soil. Large amounts of P fertilizer are required to sustain high yields, which is both inefficient and hazardous to the environment. Plants have evolved various adaptive responses to cope with low external P availability, including mobilizing cellular P through phosphate (Pi) transporters and recycling Pi from P-containing biomolecules to maintain cellular P homeostasis. This mini-review summarizes the current research on intracellular P recycling and mobilization in response to P availability. We introduce the roles of Pi transporters and the P metabolic enzymes and expand on their gene regulation and mechanisms. The relevance of these processes in the search for targets to improve phosphorus use efficiency and some of the current challenges and gaps in our understanding of P starvation responses are discussed.

The development of the water transporting xylem tissue in plants involves an intricate interplay of Rho-of-Plants (ROP) proteins and cortical microtubules to generate highly functional secondary cell wall patterns, such as the ringed or spiral patterns in early-developing protoxylem. We study the requirements of protoxylem microtubule band formation with simulations in CorticalSim, extended to include finite microtubule persistence length and a novel algorithm for microtubule-based nucleation. We find that microtubule flexibility facilitates pattern formation for all realistic degrees of mismatch between array and pattern orientation. At the same time, flexibility leads to more density loss, both from collisions and the microtubule-hostile gap regions, making it harder to maintain microtubule bands. Microtubule-dependent nucleation helps to counteract this effect by gradually shifting nucleation from the gap regions to the bands as microtubules disappear from the gaps. Our results reveal mechanisms that can result in robust protoxylem band formation.

In ‘The chemical basis of morphogenesis’ (1952), Alan Turing introduced an idea that revolutionised our thinking about pattern formation. He proposed that diffusion could lead to the spontaneous formation of regular patterns. Here, we discuss the impact of Turing’s idea on plant science using three well-established examples at different scales: ROP patterning inside single cells, epidermal patterning across several cells and whole vegetation patterns. Also at intermediate levels, e.g., organ spacing, plants look surprisingly regular. But not all regular patterns are Turing patterns, careful observation and prediction of the patterning process—not just the final pattern—is critical to distinguish between mechanisms.