A plant’s roots interact with the diverse microbes inhabiting its neighborhood — the rhizosphere, illustrated here by a model. The soil surrounding plant roots teems with microorganisms that are both helpful and hostile. To better understand these connections, researchers are investigating how root metabolism determines the chemical signals roots emit; the subsequent effect on soil microbes; and ultimately on plant health and production.
The creation of new biological tools will permit the researchers to use their findings to modify plant genomes specifically targeting traits such as drought resistance and yield.
Corn plants possess both male and female flowers. The male flower called a tassel is laced with pollen and sprouts atop each plant. When the wind blows, pollen from the tassel shakes loose and falls on the silks below that are attached to newly formed ears of corn (the female flower). Without the tassel, no edible ears will form.
Researchers are now using machine learning to monitor pollen production in corn plants. The bright pink coloration on the tassel (right) shows the density of the pollen-producing anthers. Although male sterile plants are useful for making hybrid seeds, the loss of male fertility in crop plants can greatly reduce seed yield. This new quantification method can assess how variable environmental conditions cause sterile plants to revert to partial fertility or to monitor loss of male fertility.
When leaves form on the stem of a plant they may look symmetrical, but in reality, they’re not. By studying patterns of the plant hormone auxin, researchers have discovered that auxin concentrations cause asymmetry at the molecular and anatomical levels, altering gene expression and leaf shape. In this way, the plant produces the leaf shape and orientation it needs to survive. This research offers an opportunity to examine the mechanisms plants use to produce an immense variety of leaf shapes in predictable arrangements.
One of the plants used in this research was the weed Arabidopsis. Back in 1990, NSF joined with other U.S. federal agencies to launch the Arabidopsis thaliana Genome Research Project. The initiative required international collaboration and fostered advances that revolutionized plant science including sequencing the entire Arabidopsis genome. This was the first plant genome sequenced and it emerged as the plant counterpart to the lab mouse since it served as a model for over 250,000 plant species
The plant hormones auxin (green) and cytokinin (red) light up the cells in the tip of this soybean root. These two hormones play a major role in determining the shape and extent of root systems, which help plants obtain nutrients and water from the soil.
A team of researchers used image analysis methods to quantify outputs of these hormones in soybean root and nodule cells to understand how the ratio between the hormones gives specific identity and functionality to each cell. This information can help develop crop plants with better root systems and nodules for enhanced water and nutrient acquisition, and thus enhance sustainable food production and ensure food security.
This tour through NSF’s many contributions to plant research highlights the agency’s commitment to supporting basic research that ensures the global harvest keeps pace with human needs.
The images in this National Science Foundation gallery are copyrighted and may be used only for personal, educational and nonprofit/non-commercial purposes. Credits must be provided.
Strands of goatgrass, specifically Aegilops tauschii, a wild ancestor of bread wheat, contain a genetic map for a highly adaptable, disease tolerant form of wheat. But when researchers began trying to extract that map for practical use nearly 20 years ago, they lacked the tools to sequence a highly complex genome that rivals the size of the human genome.
However, recent technology advances allowed the researchers to generate a genome sequence for A. tauschii. The sequence is the primary source of genes for the bread-making properties of wheat flour. This finding will enable the researchers to investigate new genes to improve wheat baking quality, disease resistance and tolerance to conditions such as frost and drought. Researchers have already discovered two new genes that help wheat resist a strain of wheat stem rust, a blight that overruns wheat. The genes are now available to wheat breeders.
Plants “breathe” using pores on the underside of their leaves called stomata. Recently, researchers engineered plants to conserve 25 percent more water by only partially opening these tiny, lip-like orifices. Developing more water-efficient plants could help ease future crop production in locations with limited water supplies.
These blue blips are chromosomes with synthetically engineered minichromosomes made visible by “painting” DNA with a fluorescent marker (red dots at yellow arrows). These artificial chromosomes are a new way to introduce alternate traits into plants for breeding or to study gene function.
The technology opens the door for generating plants that are “hand-made” for specific environments. Engineering chromosomes will also allow for rapid testing of predictions about how the addition of genes affects plant traits. This work could potentially reduce the years required to breed a new trait into a crop.
This intimate portrait of algae (red) living within the tentacles of its host, a sea anemone (green outline), shows the mutually beneficial connection between plant and animal. The algae use energy from sunlight to make sugars from carbon dioxide and water and give up to 90 percent of this sugar to their host, in this case the anemone.
The relationship is important for productive and diverse ecosystems in coral reefs. The breakdown of their dynamic can result in the collapse of entire reef ecosystems. Understanding the cell biology that occurs throughout the relationship may offer clues to maintaining coral reef health.
As landscapes in the Northern hemisphere spring back into Technicolor bliss, consider the science behind those brilliantly colored, supple flowers, green succulent ferns and towering deciduous trees bursting forth.
Over the past two decades, the National Science Foundation (NSF) has funded multiple initiatives from genome sequencing to plant metabolism to improve our understanding of the world’s flora. These efforts are helping revolutionize agricultural science and practice. The following images provide a snapshot of this exciting research.
This top-down glimpse into an ear of corn was captured when the ear was just 5 millimeters long. Stem cells make up the twisting ribbon structure and will divide to build the ear. These cobs will be thicker than normal and possess many more rows of edible kernels. The genes that cause these large, so-called “fasciated” ears are good targets for breeding to generate higher yielding varieties.
To learn more, go to nsf.gov.
The magenta glow in this image resonates from custom light-emitting diode growth lights that are a key part of an automated system that moves plants by conveyor belts, waters them and records their daily growth. The system is part of a project that focuses on ensuring global food security by improving crop resilience. The study plants are rice and wheat, which provide more than 50 percent of caloric intake for humans worldwide. The project also features collaboration with industry to more rapidly translate research findings to farmers for practical use.
The research is part of a national effort to understand the relationship between organisms’ genetic material and their physical characteristics. Elucidating these dynamics is also at the heart of NSF’s Rules of Life initiative, one of NSF’s "10 Big Ideas for Future Investment". For plant science, this effort will help scientists predict outcomes such as whether crops will grow in extreme temperatures or whether larger leaves can improve crop yields.
Viewed with a confocal microscope, these leaf cells reveal haploid, diploid and tetraploid maize (left to right). The left cells have only one set of chromosomes, the middle cells each have a double set and the right cells have four sets. As the ploidy level increases, cell size increases proportionally.
The ploidy effect on plant architecture provides evidence for how to change the size or yield of the plant in a very targeted way. By applying confocal imaging, researchers can now quantify cell volume in addition to cell size. These two factors are providing new insights into how plant characteristics are genetically controlled. This information can ultimately guide development of new traits for agricultural use and scientific study.
The fern Pteris vittata tolerates and accumulates very high levels of the deadly toxin arsenic. But how? After sucking arsenic out of the soil and into its fronds, the plant encodes a protein that moves the poison into its equivalent of a trashcan, so that it can’t have an effect on the plant.
Through experiments, researchers discovered the gene needed for the plant to tolerate arsenic -- 100 to 1000 times more arsenic than other plants. The gene could be used to create plants that can clean up water and soils contaminated with arsenic. The finding could also help protect rice plants from accumulating harmful levels of the toxin. Rice currently is a diet staple for more than half the world’s population.