New Model for Communication in Plant Cells
A study led by the University of Maryland explains how plants communicate within cells using a protein that closely resembles an animal protein that has a role in communication between nerve cells. While plants lack a true nervous system, previous studies have shown that plants need these proteins, called glutamate receptor-like proteins (GLRs), to do important things such as mate, grow, and defend themselves against diseases and pests. In the study, researchers working with pollen cells from Arabidopsis thaliana found that these GLR proteins form the basis of a complex communication network inside individual plant cells.
The similarities between the animal nerve proteins (glutamate receptors) and the GLR plant proteins suggest that the two proteins date back to a common ancestor—a single-celled organism that gave rise to both animals and plants. Research findings suggest that GLRs rely on another group of proteins, called "cornichon" proteins, to transport GLRs to different locations in plant cells and to regulate activity of the protein within each cell. The study found that with the help of cornichon proteins, GLRs act as valves that carefully manage the concentration of calcium ions—a vital aspect of many cell communication pathways—within various structures inside the cell.
At left, normal Arabidopsis thaliana plants reproduce when pollen tubes (thin blue filaments) grow downward toward the ovules to produce seeds. At right, in a plant with a mutated glutamate receptor-like protein gene, this process happens much more slowly. Arrows in both images mark the advance of the pollen tubes at exactly the same time after pollination.
Photo Credit: José Feijó/University of Maryland
Research Unlocks Rice Gene Diversity for Food Security
A new study opens the possibility of accelerating rice breeding to help achieve food security for some of the world's most vulnerable rice farmers. A collaboration among the International Rice Research Institute (IRRI), the Institute of Crop Sciences of the Chinese Academy of Agricultural Sciences (CAAS), BGI-Shenzhen, and 13 other partner institutions, the research will enable scientists and breeders to discover new gene variants and characterize known genes for important traits, such as disease resistance and tolerance to floods, drought, and salty water. Additionally, molecular breeders could use the genetic markers to select rice plants that are more likely to carry a desired trait before they are planted in the field.
Results of the research revealed that, among the 3,000 rice genomes, there are significant variations in gene content and immense sequence variation. Researchers identified more than 10,000 new rice genes and over 29 million simple variations throughout the genome. Additionally, within the two major rice variety groups, the analysis revealed the existence of previously unreported populations that are unique to specific geographic origins. Other evidence revealed that Asian rice was domesticated multiple times thousands of years ago.
"This information leads to faster and more accurate development of varieties suited to various agricultural environments, especially for unfavorable rice-growing areas where the poorest and most vulnerable farmers reside," says Dr. Jacqueline Hughes, IRRI's Deputy Director General for Research. Dr. Kenneth McNally, IRRI senior scientist, said that this is the largest set of genomic variants discovered for a crop species that is freely and publicly available for plant breeders and scientists across the world. It already serves as material for training a new generation of plant biologists.
Plant Breeders Balance Shared Innovation, Revenue
Public-sector plant breeders (for example, at public universities) have developed crops for better productivity. As a result, more food is available to feed a growing population. This research and innovation requires funding. But funding -- and revenue from the crops developed -- is increasingly hard to obtain. In response, a group of plant breeders met in 2016 to discuss best practices. Julie Dawson, an assistant professor at the University of Wisconsin-Madison, is lead author of a recent paper summarizing their recommendations.
Intellectual property rights can protect crop varieties. And licensing can provide revenue to support further developments. But certain types of intellectual property rights can restrict plant breeders from sharing plant materials. That can limit innovation across the board. Finding a balance between these needs is tricky. It's also important: "Crop breeding is critical for the future of agriculture," says Dawson. "Plant breeding programs benefit farmers everywhere. They also benefit anyone who eats."
The group has three recommendations. They suggest developing best practices for revenue sharing. They advocate for increased funding for public programs. They also suggest establishing professional standards for sharing plant breeding materials. Historically, many crop varieties were released to the public with almost no restrictions. "But budgets are getting tighter," says Dawson. "Grant funding is also becoming more competitive. Public sector plant breeders need to seek other sources of revenue."
Carrot Breeder Philipp Simon (USDA-ARS, Madison WI) and graduate student Charlene Grahn explain their selection for stronger and more vigorous tops to improve carrot competition with weeds and ease of mechanical harvest. This complex trait is important for both conventional and organic production.
Photo Credit: Micaela Colley / Organic Seed Alliance
Plants Can Cut Indoor Air Pollution
People in industrialized countries spend more than 80% of their lives indoors, increasingly in air-tight buildings. These structures require less energy for heating, ventilating, and air conditioning, but can be hazardous to human health if particulate matter and potentially toxic gases, including carbon monoxide, ozone, and volatile organic compounds, from sources such as furniture, paints, carpets, and office equipment accumulate. Plants absorb toxins and can improve indoor air quality, but surprisingly little is known about what plants are best for the job and how we can make plants perform better indoor. In a Review published 19 April 2018 in Trends in Plant Science, Frederico Brilli, a plant physiologist at the National Research Council of Italy -- Institute for Sustainable Plant Protection, and colleagues conclude that a better knowledge of plant physiology, along with integration of smart-sensor-controlled air cleaning technologies, could improve indoor air quality in a cost-effective and sustainable way.
Plants improve air quality through several mechanisms: they absorb carbon dioxide and release oxygen through photosynthesis, they increase humidity by transpiring water vapor through microscopic leaf pores, and they can passively absorb pollutants on the external surfaces of leaves and on the plant root-soil system. But plants are usually selected for indoor use not for their air-purifying abilities but for their appearance and ability to survive while requiring little maintenance. "For most of us plants are just a decorative element, something aesthetic, but they are also something else" says Brilli. According to Brilli, such studies could show how to "optimize the use of plants indoors, in terms of how many plants per square meter we need to reduce air pollution to a certain level."
Research is also needed to understand plant microbiomes: the populations of microorganisms (bacteria and fungi) that live with plants both in the soil and on leaf surfaces. This microbiome participates in the removal of airborne pollutants, but the contribution of different microbial species to removing pollutants is currently unknown.
Plants absorb toxins and can improve indoor air quality.
Photo Credit: Photographee.eu / Fotolia
Cotton Research Goes to Space
Christopher Saski, a Clemson University associate professor of plant and environmental sciences, together with his transdisciplinary team of investigators, is sending his research on the cotton genome into outer space after being selected as a winner in the Cotton Sustainability Challenge. The Cotton Sustainability Challenge, run by the Center for the Advancement of Science in Space (CASIS) and sponsored by Target Corp., provided researchers and innovators the opportunity to propose solutions to improve crop production on Earth by sending their concepts to the International Space Station (ISS) U.S. National Laboratory.
Saski's project proposes to examine gene expression, DNA methylation patterns, and genome sequences of embryogenic callus material that respond differently to regeneration in tissue culture during the process of regeneration under micro- and normal gravity environments. This project could help unlock the phenomenon of genetic recalcitrance (resistance) to regeneration, advancing fundamental biological knowledge and can have translational impacts to other plant species that are critical to global agricultural sustainability.
Multiple Resistance Genes in Farmed Chickens
A team of investigators has isolated colistin-resistant Escherichia coli from a commercial poultry farm in China. Colistin is an antibiotic of last resort against certain bacteria. The research is published 14 May 2018 in Antimicrobial Agents and Chemotherapy. In the study, as part of ongoing surveillance, the researchers from Key Laboratory of Sichuan Province, Sichuan University collected rectal swabs from randomly selected chickens in multiple commercial chicken farms in China. The researchers found that E. coli from the chickens often carried multiple resistance genes, including one copy of the colistin-resistance gene mcr-1, and one copy of the resistance gene, mcr-3. This is the first report of these two genes on a single plasmid. "The coexistence of mcr-1 and mcr-3 in E. coli isolates may pose a huge threat to public health," said Dr. Hongning Wang, PhD, Professor of Animal Disease Prevention and Food Safety, Key Laboratory of Sichuan Province, Sichuan University.
Plasmids are genetic elements that can jump from one bacterium to another, and sometimes even from one species to another, often spreading resistance genes.The resistance genes were contained on a type of plasmid known as IncP. The researchers also found circular pieces of DNA bearing mcr-3, which were derived from IncP plasmids. These so-called circular intermediates often contain "insertion sequences" that encourage their integration into other plasmids, hastening spread of the resistance genes.
Farming Fish Saves Land, Analysis Finds
To satisfy the protein demands of an anticipated nearly 10 billion people by 2050, the United Nations' Food and Agriculture Organization (FAO) and researchers around the world estimate current animal production will need to grow by an average of 52 percent. Meeting this need without pushing the environment to the brink will be critical. New evidence shows seafood from aquatic farming -- aquaculture -- can help feed the future global population while substantially reducing one of the biggest environmental impacts of meat production -- land use -- without requiring people to entirely abandon meat as a food source.
A new study from UC Santa Barbara's National Center for Ecological Analysis and Synthesis (NCEAS) found that the amount of cropland required to support future protein needs with more farmed aquatic animals would be significantly smaller than if terrestrial livestock production met those needs. This research is the first land-use analysis of future food systems to focus on aquaculture -- the world's fastest-growing food sector -- and helps reveal its potential role in conservation and food security. The findings appear in the Proceedings of the National Academy of Sciences.
"While aquaculture can add some pressure because -- ultimately -- it is a food production system, our study demonstrates the relative amount is minuscule compared to terrestrially farmed animals," said lead author Halley Froehlich, a postdoctoral researcher at NCEAS. "Aquaculture is not going to be the main strain on future crop feed and land use. It is -- and will likely continue to be -- terrestrial livestock."
