Volume 2 Issue 4, April 2016

Our hungry world relies on a small army of crop varieties that have been developed over the past few decades. They have been bred to grow faster, sweeter and bigger, often at the expense of their nutritional value. Looking into the history of these crops could provide a solution.

A comprehensive analysis of transcripts in grafted cucumber–watermelon plants substantiates specific transcript transport to diverse tissues and provides new insights into phosphate starvation responses.

A series of genetic experiments demonstrates that small RNAs can direct gene silencing within germ cells in a non-cell-autonomous manner. This provides evidence for how plant germ and non-germ cells may communicate to maintain genome integrity during reproductive transitions.

Cultivated peanut has a large, complex genome, so obtaining its entire sequence is challenging. De novo assemblies of two diploid ancestor genomes provide high-quality reference sequences for decoding allotetraploid peanut genomes, and will become valuable resources for breeding and evolutionary studies.

Plants must adapt to unfavourable environmental conditions. Shade avoidance by organ elongation is an important mechanism to move towards sunlight. A new mutant affected in auxin conjugation shows that auxin homeostasis controls hypocotyl elongation.

The sorting of soluble proteins for degradation in the vacuole is of vital importance in plant cells, and relies on the activity of vacuolar sorting receptors (VSRs). Laboratory experiments with tobacco mesophyll protoplasts suggest that VSRs are required for the transport of ligands from the endoplasmic reticulum and Golgi to the trans-Golgi network/early endosome.

The genetic diversity of wild relatives of domesticated crops can be useful for developing more productive, nutritious and resilient crop varieties. A comparison of the modelled diversity of crop wild relatives with their representation in gene banks suggests that a systematic effort is needed to improve their conservation and availability for use in plant breeding.

The plant growth hormone auxin is involved in hypocotyl elongation in response to shade and high temperatures. The vas3 mutant now shows that local auxin conjugation is as important for controlling hormone homeostasis as biosynthesis and transport.

It is thought that siRNA derived from the transcription of transposable elements (TEs) in pollen nurse cells moves to sperm cells and represses TE activity. A study has now generated solid molecular data supporting this tantalizing but controversial hypothesis.

Photosystem I (PSI) is thought to be protected from photoinhibition by controlling electron flow from photosystem II. This report shows that PSI is sensitive to light stress but, following photodamage, functions in non-photochemical energy quenching.

In high light conditions, terrestrial plants dissipate excess energy as heat. However, microalgae such as Chlamydomonas use state transitions, not to dissipate excess light energy, but to efficiently redistribute it between the photosystems.

Signalling events of early phosphate (P_i) stress in plants are not well known. A study combining transcriptome analyses and grafting experiments now reveals tissue-specific transcriptomic responses to early P_i stress, and a major role for the vascular system in this process.