Articles in 2022

A xylan-rich nanodomain at pit boundaries of xylem vessels maintains distinct wall patterns by anchoring cellulosic nanofibrils at the pit borders. These nanocompartments are produced by the xylan synthase IRREGULAR XYLEM (IRX)10 and its homologues.

The establishment of leaf adaxial–abaxial polarity happens early at the shoot apical meristem. Using quantitative live imaging of auxin and dorsiventral polarity markers, the authors trace the origin of polarity to before primordium emergence, to an overlay of high auxin onto a meristem periphery prepattern.

In plants, impairing transgenerational resetting of juvenility leads to premature flowering in the offspring. This robust reset process is mediated by de novo activation of MIR156/7-family genes at different developmental stages through distinct reprogramming routes.

In potato, the TCP transcription factor BRANCHED1b represses aerial tuber formation in the axils of the leaves. It functions through limiting the number of plasmodesmata, reducing sucrose levels and repressing the tuberigen protein SP6A.

In Arabidopsis, microRNAs control the transition from juvenile to adult states. The study, using genomic, genetic and molecular approaches, investigates how miR156 and miR157 are re-activated at each generation.

Development of flowers typically employs conserved molecular pathways and recurrent sets of homologous genes. A new study shows that a homologue of RADIALIS, a gene well known to control flower symmetry, is recruited to serve a different function.

A method for targeted mutagenesis of mitochondrial genomes is presented. It combines site-specific DNA cleavage with selection for mutations that confer cleavage resistance, and produces genetically stable plants with edited mitochondrial genomes.

In hexaploid persimmon, the RADIALIS-like gene was identified as a key player in the reversion of male flowers to hermaphroditism. Interestingly, it acts independently of the pathways involved in the ancestral transitions away from hermaphroditism.

Assemblies of six representative perennial Glycine genomes and a comparison with annual soybean genomes reveal evolutionary patterns, differentiation and adaptation of annual and perennial genomes and mechanisms driving subgenome fractionation.

A recent study suggests that the optimal temperature for symbiotic nitrogen fixation rates exceeds the plant’s preferred growth temperature in laboratory conditions. A few degrees of warming could thereby increase or decrease nitrogen fixation rates, depending on the optimal rate among species.

New evidence that a mid-Cretaceous fossil represents a modern angiosperm genus partly reinstates Darwin’s view of the fossil record.

Growth defects associated with disruption of the mildew susceptibility gene MLO are rescued in bread wheat and Arabidopsis by transcriptional activation of a proximal monosaccharide transporter

Thousands of plants are known to be edible, yet we lack nutritional data for many of them. This study predicts the B-vitamin profiles for edible plants and finds many have the potential to help alleviate deficiencies and should be conservation priorities.

It has been calculated that 14% of the world’s tree species are yet to be identified. But is that a lot or a little?

The difference in phloem pressure is the driving force that moves photosynthetic products and other solutes from the source to the sink. Measurements with emerging technologies reveal that sugar loading is not essential for maintaining phloem pressure and phloem bulk flow in the maize sugar-loading-defective mutant sut1.

The cryo-EM structure of the PSI–LHCI photosystem supercomplex from Physcomitrium patens shows that the red-shifted Lhca4 antenna is replaced by an Lhca2 paralogue. The structure demonstrates an adaptation of mosses to low light.

Loading of osmolytes into the phloem drives a pressure-flow transport mechanism. A maize sucrose transporter1 loss-of-function mutant has much reduced export of carbon from leaves, but increased potassium concentrations maintain phloem pressure.