Volume 5 Issue 6, June 2019

Ion channels and transporters can integrate environmental cues in the cell. In addition to governing calcium homeostasis, a chloroplast envelope-localized calcium channel is now characterized to implicate chloroplast calcium signalling in drought tolerance.

Root growth depends on the shoot-to-root transport of assimilates through the phloem, which is connected to the meristems by plasmodesmata pores. A PHLOEM UNLOADING MODULATOR is now identified to regulate plasmodesmata internal organisation, leading to pores that appear tighter but are more efficient for transport.

This Review uses Golden Rice and omega-3 fish oil crops as examples to evaluate the progresses, problems and challenges associated with the development of nutritionally enhanced crops by genetic modification.

Volatile organic compounds from plants are an integral part of atmospheric chemistry and ecosystem interactions, especially in an Arctic region impacted by climate change. Observed increases in insect herbivores leads to a substantial increase in VOC emissions, showing a link between warming and plant impacts.

By map-based cloning and knockout experiments, a study identified and validated ZmDMP to be one of the two genes known to control haploid induction in maize. A single-nucleotide mutation in ZmDMP causes a 2–3-fold increase in the haploid induction rate.

Calcium (Ca²⁺) is one of the most important second messengers in plant signalling, but high-level accumulation in cytosol causes toxicity. Now, a chloroplast calcium uniporter has been found to mediate Ca²⁺ influx from cytosol to chloroplast and, interestingly, regulate plant responses to osmotic stress.

A study reports the crystal structures of the Arabidopsis thaliana cytochrome P450 monooxygenase CYP90B1—a rate-limiting enzyme of the brassinosteroid biosynthetic pathway—complexed with its substrate or inhibitors for brassinosteroid biosynthesis, providing insights into its function.

Thousands of varieties of wine grapes have been recorded and described in historical accounts, some going back as far as the Middle Ages, but genetic relationships between ancient and modern varieties were unknown. Genomic sequencing of 28 seeds, dating back as far as the Iron Age, finds close relationships to today’s cultivars, including a genetic match to Savagnin Blanc from 1100 ce.

Plasmodesmata channel substance transportation between neighbouring cells, including the sieve tube elements and the phloem companion cells. Now, the plasmodesmal ultrastructure is shown to be regulated by a newly identified phloem unloading modulator that participates in sphingolipid biosynthesis in Arabidopsis.

MYC2 is a master component of jasmonate signalling, working in concert with MED25, a subunit of the Mediator transcriptional co-activator complex. Here it is shown that MYC2 and MED25 have largely overlapping targets and mediate DNA looping between these enhancer and promoter sequences.

This cryo-electron microscopy structure of a photosystem I–light-harvesting complex I supercomplex from Chlamydomonas reveals eight Lhca proteins forming two tetrameric light-harvesting complex I belts on one side, and a Lhca heterodimer on the other.