Autophagy mediates temporary reprogramming and dedifferentiation in plant somatic cells

Abstract

Somatic cells acclimate to changes in the environment by temporary reprogramming. Much has been learned about transcription factors that induce these cell‐state switches in both plants and animals, but how cells rapidly modulate their proteome remains elusive. Here, we show rapid induction of autophagy during temporary reprogramming in plants triggered by phytohormones, immune, and danger signals. Quantitative proteomics following sequential reprogramming revealed that autophagy is required for timely decay of previous cellular states and for tweaking the proteome to acclimate to the new conditions. Signatures of previous cellular programs thus persist in autophagy‐deficient cells, affecting cellular decision‐making. Concordantly, autophagy‐deficient cells fail to acclimatize to dynamic climate changes. Similarly, they have defects in dedifferentiating into pluripotent stem cells, and redifferentiation during organogenesis. These observations indicate that autophagy mediates cell‐state switches that underlie somatic cell reprogramming in plants and possibly other organisms, and thereby promotes phenotypic plasticity.

The Arabidopsis Calcium Sensor Calmodulin-like 38 Regulates Stress Granule Autophagy and Dynamics during Low Oxygen Stress and Re-aeration Recovery

“…An unexpected finding in the present study is that a second phase of autophagy is induced upon reoxygenation, with autophagosomes appearing and peaking within minutes of the return of molecular oxygen followed by gradual disappearance as recovery proceeds. Recent work suggests that similar rapid and transient autophagic bursts may be a common reprogramming response to several hormonal and environmental signals that helps facilitate the rapid removal of unnecessary cellular components, and is necessary for the establishment of new programs (Rodriguez et al, 2020). In this regard, it important to consider that the post-hypoxia reoxygenation triggers a complex metabolic reprograming response as well as generating its own set of stresses.…”

Bacterial-type plant ferroxidases tune local phosphate sensing in root development

“…Primary root tips were excised and collected into liquid nitrogen. Tissue lysis, sample preparation, protein labeling, Tandem-Mass-Tag (TMT) spectrometry, MS/MS data analysis, and TMT-quantifications were performed as recently described (Rodriguez et al, 2020; Stephani et al, 2020).…”

Cellular plasticity at the nexus of development and disease

“…Autophagic puncta accumulate in these reprogramming cells, and autophagy inhibition blocks transdifferentiation initiation, whereas autophagy stimulation (by blocking mTORC1) increases its efficiency and efficacy. The requirement of autophagy for plasticity may be universal as even plant cells use autophagy for climatic adaptation (Rodriguez et al, 2020). Accordingly, Dr Mishra showed that autophagy is also required for transdifferentiation of pancreatic duct cells into endocrine cells.…”