Login


Plant scientists untangle the molecular mechanisms connecting plant stress and growth

Iowa State University researchers for the first time have mapped the various molecular components that govern how environmentally stressed plants interrupt their normal growth pathways by tapping into an important energy recycling function.

The research, published in the peer-reviewed academic journal Developmental Cell, shows that autophagy, a system by which both plants and animals recycle energy and molecular components, plays a key role in slowing plant growth during times of stress.

Yanhai Yin, a professor of genetics, development and cell biology and a Plant Sciences Institute Faculty Scholar, said plants slow their growth when they experience stress such as drought, a prolonged lack of sunlight or any other low-energy circumstance. But teasing out the genetic interactions that result in slower growth has puzzled scientists for years.

Yin and his colleagues have focused their research on a gene known as BES1, which promotes plant growth in response to a plant hormone called brassinosteroid. In their latest paper, the researchers demonstrate that stress sets off a series of reactions that allow autophagy to inhibit plant growth.

One of these reactions involves a protein known as DSK2 that acts like a bridge linking BES1 and the autophagy pathway, said Trevor Nolan, a doctoral student in Yin's lab and the lead author of the paper.

Diane Bassham, a professor of genetics, development and cell biology and the Walter E. and Helen Parke Loomis Professor of Plant Physiology, also contributed to the research team.

"We have been studying autophagy for a number of years as a process for bulk digestion of cell contents during environmental stress," Bassham said. "This recent work shows that it can also act in an exquisitely selective pathway for the digestion of a single growth regulator to coordinate growth with stress responses."

Justin Walley, an assistant professor of plant pathology and microbiology, used a high-resolution analytical technique called mass spectrometry to monitor protein modification, which showed the targeting of BES1 to autophagy by DSK2 is modified by a protein called BIN2, another key player in the brassinosteroid signaling pathway.

"We're really excited by the discovery that BIN2 modifies DSK2, and that this modification is actually responsible for controlling the balance between plant growth and plant stress responses," Walley said.

Nolan said the discovery could help plant breeders create crop varieties that can continue to grow under stressful situations. But, because autophagy plays an important role in animals as well as plants, the research could have implications beyond plant science.

"Understanding the basic science of how these processes are regulated could have implications not just for plants but for human health as well," Yin said.

This research was supported by the ISU Plant Sciences Institute and by a grant from the National Institutes of Health recently awarded to the team to continue studying the interaction between brassinosteroid and autophagy pathways.

Read the paper: Selective Autophagy of BES1 mediated by DSK2 balances plant growth and survival.

Article source: Iowa State University.

Image credit: Hao Jiang

News

How plants form their sugar transport routes

In experiments on transport tissues in plants, researchers from Heidelberg University were able to identify factors of crucial importance for the formation of the plant tissue known as phloem. According to Prof. Dr Thomas Greb of the Centre for Organismal Studies (COS), these factors differ from all previously known factors that trigger the specification of cells. The findings of the Heidelberg researchers substantially expand our understanding of the metabolic processes in plants. Their results were published in the journal Current Biology.


Scientists examine impact of high-severity fires on conifer forests

The ability of some Western conifer forests to recover after severe fire may become increasingly limited as the climate continues to warm, scientists from the Smithsonian Conservation Biology Institute (SCBI) and Harvard Forest found in a new study published in Global Change Biology. Although most of these cone-bearing evergreen trees are well adapted to fire, the study examines whether two likely facets of climate change -- hotter, drier conditions and larger, more frequent and severe wildfires -- could potentially transform landscapes from forested to shrub-dominated systems.


From Elsevier: 200 Years of Flora - free access to all articles

2018 will mark the 200th anniversary of the journal Flora. To kickstart the celebrations, all journals in the Elsevier archives have been scanned and have been added to ScienceDirect. Articles published before 1905 are available via the Biodiversity Library, and all articles from 1905 onwards are freely available via ScienceDirect until March 2020 and can be accessed through this page: https://www.journals.elsevier.com/flora/news/200-years-of-flora-free-access-to-all-articles.