Lee Miller vividly recalls the day in 2021 when he met a woman who had lost the function of her vocal cords. In hoarse, whispering tones she explained how her voice had been instrumental to her vocation. Losing it, she said, undercut her life’s purpose. He had to listen carefully to hear her faint words, but the lesson “was really powerful.”
The genetics behind the alternating sexes of walnut trees has been revealed by biologists at the University of California, Davis. The research, published Jan. 3 in Science, reveals a mechanism that has been stable in walnuts and their ancestors going back 40 million years — and which has some parallels to sex determination in humans and other animals.
Rice is a staple food crop for more than half the world’s population, but most farmers don’t grow high-yielding varieties because the seeds are too expensive. Researchers from the University of California’s Davis and Berkeley campuses have identified a potential solution: activating two genes in rice egg cells that trigger their development into embryos without the need for fertilization, which would efficiently create high-yielding clonal strains of rice and other crops.
For many plants, more branches means more fruit. But how does a plant branch or not branch? New research from the Department of Plant Biology has shown how plants break down the hormone strigolactone, which suppresses branching, to become more “bushy.” Using a combination of structural biology, biochemistry, and genetic engineering, the team confirmed the specific enzymes responsible for dismantling strigolactone, and their mechanism. Understanding how strigolactone is regulated could have big implications for many crop plants.
Plants need to be able to communicate with themselves—by sending signals from their leaves to their roots to their flowers—so that they can coordinate growth and optimize resource use. They also need to communicate with other plants and organisms, which they achieve by releasing volatile organic compounds (VOCs), tiny molecules that are often associated with distinct smells. Scientists know a lot about how plants emit these odorous signals, however very little is known about how they receive and interpret them.
Sorghum, or broomcorn, is a staple crop in sub-Saharan Africa, but approximately 20% of annual yields are lost due to infections with witchweed (Striga hermonthica), a parasitic plant that steals nutrients and water by latching onto the plant’s roots.
A promising new fungicide to fight devastating crop diseases has been identified by researchers at the University of California, Davis. The chemical, ebselen, prevented fungal infections in apples, grapes, strawberries, tomatoes and roses, and improved symptoms of pre-existing fungal infection in rice.
Plants have to be flexible to survive environmental changes, and the adaptive methods they deploy must often be as changeable as the shifts in climate and condition to which they adapt. To cope with drought, plant roots produce a water-repellent polymer called suberin that blocks water from flowing up towards the leaves, where it would quickly evaporate. Without suberin, the resulting water loss would be like leaving the tap running.
Female zebrafish (Danio rerio) have an unusual tendency: if their egg cells are damaged, they can turn into males. Bruce Draper, a professor in the Department of Molecular and Cellular Biology (MCB) and Florence Marlow, a professor at the Icahn School of Medicine at Mount Sinai, have discovered that immune cells called macrophages play a key role in this process. These cells normally keep things “tidy” by removing dead or damaged cells – but in zebrafish they can also remodel the ovaries into sperm-producing testes. “It’s a pretty interesting and novel idea,” says Draper.
Maize is one of the world’s most widely grown crops. It is used for both human and animal foods and holds great cultural significance, especially for indigenous peoples in the Americas. Yet despite its importance, the origins of the grain have been hotly debated for more than a century. Now new research, published Dec. 1 in Science, shows that all modern maize descends from a hybrid created just over 5000 years ago in central Mexico, thousands of years after the plant was first domesticated.
