Stimulating photosynthetic processes increases productivity and water-use efficiency in the field
López-Calcagno et al. report on the introduction of the cyanobacterial bifunctional enzyme fructose-1,6-bisphosphatase/sedoheptulose-1,7-bisphosphatase or the overexpression of the plant enzyme sedoheptulose-1,7-bisphosphatase, together with the expression of the red algal protein cytochrome c6, and show that a further increase in biomass accumulation under both glasshouse and field conditions can be achieved. Furthermore, they provide evidence that the stimulation of both electron transport and RuBP regeneration can lead to enhanced intrinsic water-use efficiency under field conditions.
Disentangling dimensions of phytochemical diversity: alpha and beta have contrasting effects on an insect herbivore
Phytochemical diversity is comprised of two main dimensions – the average (alpha) within plant neighbors or the difference (beta) in the composition of chemicals between plant neighbors. Research, however, has primarily examined the consequences of phytochemical diversity on herbivore performance through a single dimension even though diversity is multi‐dimensional. Furthermore, the ecological role of phytochemical diversity is not well understood because each of these dimensions exhibits unique biological effects on herbivore performance. Therefore, it has been difficult to tease apart the relative importance of alpha and beta chemical diversities on plant‐herbivore interactions. Glassmire et al. experimentally manipulated alpha and beta diversities along a chemical gradient to disentangle the relative effects of these dimensions on the performance of a mobile generalist herbivore, Trichoplusia ni (Hübner), using 16 genotypes from the Solanum pennellii introgression lines.
Improving plant gene regulatory network inference by integrative analysis of multi-omics and high resolution datasets
Gene regulatory networks (GRNs) model the interactions between gene expression regulators and their targets that mediate a myriad of biological functions. Constructing GRNs that integrate multiple data types at increased resolution is improving our understanding of the complex regulatory mechanisms controlling different biological processes in plants. Going beyond transcription factor binding and transcriptome profiles, GRNs that incorporate multiple data types, including chromatin accessibility and long-range chromatin interaction, TF binding site motifs, microRNA, ribosome-associated RNA, and proteomic profiles, were constructed for several cell types and multiple species. The rise of single-cell RNA-seq applications in plants opens up possibilities for studying cell type-specific GRNs in the processes of cell differentiation, development and responses to the environment.
Current Opinion in Systems Biology
BonnMu: a sequence-indexed resource of transposon-induced maize mutations for functional genomics studies
Sequence-indexed insertional libraries in maize (Zea mays L.) are fundamental resources for functional genetics studies. Marcon et al. constructed a Mutator (Mu) insertional library in the B73 inbred background designated BonnMu. A total of 1,152 Mu-tagged F2-families were sequenced using the Mu-seq approach. They detected 225,936 genomic Mu insertion sites and 41,086 high quality germinal Mu insertions covering 16,392 of the annotated maize genes (37% of the B73v4 genome). On average, each F2-family of the BonnMu libraries captured 37 germinal Mu insertions in genes of the Filtered Gene Set (FGS).
Structural basis of salicylic acid perception by Arabidopsis NPR proteins
Salicylic acid (SA) is a plant hormone that is critical for resistance to pathogens. The NPR proteins have previously been identified as SA receptors, although how they perceive SA and coordinate hormonal signalling remain unknown. Wang et al. report the mapping of the SA-binding core of Arabidopsis thaliana NPR4 and its ligand-bound crystal structure. The SA-binding core domain of NPR4 refolded with SA adopts an α-helical fold that completely buries SA in its hydrophobic core. The lack of a ligand-entry pathway suggests that SA binding involves a major conformational remodelling of the SA-binding core of NPR4, which they validated using hydrogen–deuterium-exchange mass spectrometry analysis of the full-length protein and through SA-induced disruption of interactions between NPR1 and NPR4. They show that, despite the two proteins sharing nearly identical hormone-binding residues, NPR1 displays minimal SA-binding activity compared to NPR4.
Structural basis for VIPP1 oligomerization and maintenance of thylakoid membrane integrity
Vesicle-inducing protein in plastids (VIPP1) is essential for the biogenesis and maintenance of thylakoid membranes, which transform light into life. However, it is unknown how VIPP1 performs its vital membrane-shaping function. Kumar Gupta et al. use cryo-electron microscopy to determine structures of cyanobacterial VIPP1 rings, revealing how VIPP1 monomers flex and interweave to form basket-like assemblies of different symmetries.
The ecological and evolutionary consequences of systemic racism in urban environments
Urban areas are dynamic ecological systems defined by interdependent biological, physical, and social components. The emergent structure and heterogeneity of the urban landscape drives the biotic outcomes observed, and such spatial patterns are often attributed to the unequal stratification of wealth and power in human societies. Despite these patterns, few studies effectively consider structural inequalities as drivers of ecological and evolutionary outcomes, instead focusing on indicator variables such as neighborhood wealth. Schell et al. explicitly integrate ecology, evolution, and social processes to emphasize the relationships binding social inequities, specifically racism, and biological change in urbanized landscapes
Soil carbon loss by experimental warming in a tropical forest
Nottingham et al. show that in situ experimental warming of a lowland tropical forest soil on Barro Colorado Island, Panama, caused an unexpectedly large increase in soil CO2 emissions. Two years of warming of the whole soil profile by four degrees Celsius increased CO2 emissions by 55 per cent compared to soils at ambient temperature. The additional CO2 originated from heterotrophic rather than autotrophic sources, and equated to a loss of 8.2 ± 4.2 (one standard error) tonnes of carbon per hectare per year from the breakdown of soil organic matter.
Structure of the activated Roq1 resistosome directly recognizing the pathogen effector XopQ
Plants and animals detect pathogen infection via intracellular nucleotide-binding leucine-rich repeat receptors (NLRs) that directly or indirectly recognize pathogen effectors and activate an immune response. How effector sensing triggers NLR activation remains poorly understood. Martin et al. describe the 3.8 Å resolution cryo-electron microscopy structure of the activated Roq1, an NLR native to Nicotiana benthamiana with a Toll-like interleukin-1 receptor (TIR) domain, bound to the Xanthomonas effector XopQ.
The manifold actions of signaling peptides on subcellular dynamics of a receptor specify stomatal cell fate
Receptor endocytosis is important for signal activation, transduction, and deactivation. However, how a receptor interprets conflicting signals to adjust cellular output is not clearly understood. Using genetic, cell biological, and pharmacological approaches, Qi et al. report here that ERECTA-LIKE1 (ERL1), the major receptor restricting plant stomatal differentiation, undergoes dynamic subcellular behaviors in response to different EPIDERMAL PATTERNING FACTOR (EPF) peptides. Activation of ERL1 by EPF1 induces rapid ERL1 internalization via multivesicular bodies/late endosomes to vacuolar degradation, whereas ERL1 constitutively internalizes in the absence of EPF1. The co-receptor, TOO MANY MOUTHS is essential for ERL1 internalization induced by EPF1 but not by EPFL6.