Trehalose 6-phosphate promotes seed filling by activating auxin biosynthesis

November 05, 2020

Efficient deposition of storage compounds in seeds is a key determinant of crop yield, but the underlying regulatory network of seed filling remains undefined. For many years, researchers have been working on the role of sugars for spatial regulation of seed growth and storage (Borisjuk et al., 2002). In addition to their role as a carbon source for starch and protein biosynthesis, sugar molecules have important signaling functions. Numerous studies on the model plant Arabidopsis suggested that the signaling sugar trehalose 6-phosphate (T6P) forms an essential part of a signaling network regulating plant performance in general (Figueroa and Lunn, 2016). The small size of Arabidopsis seeds, however, presents practical difficulties in investigating how T6P participates precisely in the regulation of seed filling. Therefore, the researchers made use of the larger size of pea seeds, allowing an easy preparation and compositional analysis of individual embryos. Their results have recently been published in the magazine New Phytologist.

"Our work identified T6P as a key regulator of seed filling in the grain legume pea and highlighted a link between T6P and the major plant hormone auxin", says Dr. Tobias Meitzel, researcher at IPK and first-author of the study. "This discovery represents a significant step forward in understanding interactions between metabolites and hormones with T6P reporting the raising sucrose status in the maturing seed. As a result of this, T6P mediates the activation auxin biosynthesis, which leads to a stimulation of embryo growth and reserve starch accumulation."

To better understand how T6P controls seed filling, researchers engineered transgenic pea plants aiming on the embryo?specific modulation of T6P levels. An impressive outcome of the targeted reduction of embryonic T6P content was a strongly wrinkled seed phenotype similar to that studied by Gregor Mendel in the mid term of the nineteenth century. "Nuclear magnetic resonance imaging of these embryos revealed a substantial impairment in the formation of a spatial gradient in storage product accumulation and tissue differentiation of embryos", says Dr. Ljudmilla Borisjuk, head of the research group Assimilate Allocation and NMR at IPK. "These findings explain many of the observations we already made two decades ago, when we first described the wave-like differentiation pattern of storing legume embryos."

This study is also of interest for various other areas of plant research as our findings identified T6P as an upstream regulator of auxin biosynthesis. "This hitherto unknown interaction between T6P and auxin might play a general role in mediating the sugar-auxin link", says Dr. Tobias Meitzel. It will be of ongoing interest to determine how this relationship fits within the current understanding of the regulatory frameworks surrounding growth processes and developmental transitions in plants.

Leibniz Institute of Plant Genetics and Crop Plant Research

Related Embryos Articles from Brightsurf:

Zebrafish embryos help prove what happens to nanoparticles in the blood
What happens to the nanoparticles when they are injected into the bloodstream, for example, to destroy solid tumours?

Artificial intelligence system developed to help better select embryos for implantation
Investigators from Brigham and Women's Hospital and Massachusetts General Hospital are developing an artificial intelligence system with the goal of improving IVF success by helping embryologists objectively select embryos most likely to result in a healthy birth.

Embryos taking shape via buckling
The embryo of an animal first looks like a hollow sphere.

Who's your daddy? Male seahorses transport nutrients to embryos
New research by Dr Camilla Whittington and her team at the University of Sydney has found male seahorses transport nutrients to their developing babies during pregnancy.

Study suggests embryos could be susceptible to coronavirus
Genes that are thought to play a role in how the SARS-CoV-2 virus infects our cells have been found to be active in embryos as early as during the second week of pregnancy, say scientists at the University of Cambridge and the California Institute of Technology (Caltech).

Spawning fish and embryos most vulnerable to climate's warming waters
Spawning fish and embryos are far more vulnerable to Earth's warming waters than fish in other life stages, according to a new study, which uniquely relates fish physiological tolerance to temperature across the lifecycles of nearly 700 fish species.

Animal embryos evolved before animals
A new study by an international team of researchers, led by scientists from the University of Bristol and Nanjing Institute of Geology and Palaeontology, has discovered that animal-like embryos evolved long before the first animals appear in the fossil record.

Choosing the best embryos
Struggling with infertility? You are not alone. Infertility affects one out of every six Canadian couples.

Turtle embryos play a role in determining their own sex
In certain turtle species, the temperature of the egg determines whether the offspring is female or male.

Early in vitro testing for adverse effects on embryos
ETH researchers have combined embryonic cells and liver cells in a new cell culture test.

Read More: Embryos News and Embryos Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to