Researchers at the University of Cincinnati and Florida State University have confirmed evidence of domesticated sunflowers in Mexico — 4,000 years before what had been previously believed.

“People sometimes ask “What is the big deal about sunflower?” says David Lentz, professor of biological sciences and executive director of the Center for Field Studies in the McMicken College of Arts & Sciences at the University of Cincinnati (UC). Lentz worked with Mary Pohl from Florida State University, José Luis Alvarado from Mexico’s Institute of Anthropology and History, and Robert Bye from the Independent National University of Mexico.

“First of all, sunflower is one of the world's major oil seed crops and understanding its ancestry is important for modern crop-breeding purposes," Lentz says. "For a long time, we thought that sunflower was domesticated only in eastern North America, in the middle Mississippi valley — Arkansas, Missouri, Tennessee, Illinois. This is what traditional textbooks say. Now it appears that sunflower was domesticated independently in Mexico."

"The Mexican sunflower discovery suggests that there may have been some cultural exchange between eastern North America and Mesoamerica at a very early time,” Lentz adds. “Now the textbooks need to be rewritten.”

Half a century after the last earth-shattering atomic blast shook the Pacific atoll of Bikini, the corals are flourishing again. Some coral species, however, appear to be locally extinct.

These are the findings of a remarkable investigation by an international team of scientists from Australia, Germany, Italy, Hawaii and the Marshall Islands. The expedition examined the diversity and abundance of marine life in the atoll.

One of the most interesting aspects is that the team dived into the vast Bravo Crater left in 1954 by the most powerful American atom bomb ever exploded (15 megatonnes - a thousand times more powerful than the Hiroshima bomb). The Bravo bomb vapourised three islands, raised water temperatures to 55,000 degrees, shook islands 200 kilometers away and left a crater 2km wide and 73m deep.

The world’s oldest recorded tree is a 9,550 year old spruce in the Dalarna province of Sweden.

The spruce tree has shown to be a tenacious survivor that has endured by growing between erect trees and smaller bushes in pace with the dramatic climate changes over time.

For many years the spruce tree has been regarded as a relative newcomer in the Swedish mountain region.

”Our results have shown the complete opposite, that the spruce is one of the oldest known trees in the mountain range,” says Leif Kullman, Professor of Physical Geography at Umeå University.

As the planet's population continues to grow, optimal crops need to be planted and harvested in order to feed people. One concern about widespread use of 'organic' cropping is that it would raise the price of food and have lower yields. Right now only rich people can afford organic food but if lower yields were worldwide only rich people could afford food at all, say critics.

It's not a huge issue, at least for some crops, say scientists at the University of Wisconsin-Madison and agricultural consulting firm AGSTAT. They say organic cropping systems are as productive as conventional systems for alfalfa and wheat and are almost as productive for corn and soybeans, according to research reported in Agronomy Journal.

Genetic modification holds the promise of bringing locally grown food crops to climates where farming has been traditionally difficult. Doing that means optimizing the genetics of crops in some ways without impacting them in others.

A new tool for rice genetics has made that a little bit easier. It allows rice breeders to surgically inactivate genes that confer unwanted properties.

There are many different strains of rice grown in different parts of the world and they have thrived because they are adapted to the region they grow in. In the past, introducing a gene with a beneficial modification would require years and years of breeding so that the other genes responsible for the target strains being so well adapted to their local environment were not impacted.

Crop scientists have cloned a gene that controls the shape of tomatoes, a discovery that could help unravel the mystery behind the huge morphological differences among edible fruits and vegetables, as well as provide new insight into mechanisms of plant development.

The gene, dubbed SUN, is only the second ever found to play a significant role in the elongated shape of various tomato varieties, said Esther van der Knaap, lead researcher in the study and assistant professor of horticulture and crop science at Ohio State University’s Ohio Agricultural Research and Development Center (OARDC) in Wooster.

Plant leaves are photosynthetic organs. Their main job is to harvest energy from sunlight, and use that energy to convert carbon dioxide and water into carbohydrates. In addition to capturing sunlight, leaves need to be good at doing two other things - taking up carbon dioxide and conserving water. These requirements conflict - anything that lets carbon dioxide in also lets water out. To deal with these conflicting requirements, plants produce a waterproof cuticle and regulate carbon dioxide uptake by opening and closing their stomata.

Photosynthetic rates tend to be limited by whatever is in shortest supply - water, light, carbon dioxide, nitrogen to make enzymes... If you never water your plants, they will die regardless of how much carbon dioxide and fertiliser you give them. But no matter how much water, light and carbon dioxide they have, if nitrogen is in short supply they can't make enzymes to run photosynthesis.

For plants in wet environments, access to water isn’t their biggest problem. When plants experience precipitation every day, access to carbon dioxide is likely to be more important than access to water. Since carbon dioxide is less soluble in water than in air, the presence of water on the leaf surface may hinder the uptake of water by the plant. It has been suggested that in environments like these, selection should favour the ability to rapidly shed water from leaves.

Scientists at the John Innes Centre in Norwich have discovered how roots find their way past obstacles to grow through soil. The discovery also explains how germinating seedlings penetrate the soil without pushing themselves out as they burrow.

“The key is in the fuzzy coat of hairs on the roots of plants” says Professor Liam Dolan. “We have identified a growth control mechanism that enables these hairs to find their way and to elongate when their path is clear”.

Root hairs explore the soil in much the same way as a person would feel their way in the dark. If they come across an obstacle, they feel their way around until they can continue growing in an opening. In the meantime, the plant is held in place as the hairs grip the soil.

Biologists have elucidated the mechanism of a plant gene that controls the amount of atmospheric ozone entering a plant’s leaves and their finding helps explain why rising concentrations of carbon dioxide in the atmosphere may not necessarily lead to greater photosynthetic activity and carbon sequestration by plants as atmospheric ozone pollutants increase.

It also provides a new tool for geneticists to design plants with an ability to resist droughts by regulating the opening and closing of their stomata—the tiny breathing pores in leaves through which gases and water vapor flow during photosynthesis and respiration.

Anoop Sindhu and colleagues report on a gene that may have played a key role in the evolution of grasses. The gene, Hm1, provides resistance against Cochliobolus carbonum race 1 (CCR1), a fungus that is capable of attacking and killing corn at any stage of its development (images of CCR1 infection). While CCR1 is only known to affect corn, the gene Hm1 and its relatives are present throughout the grass family, but are absent from other lineages.

CCR1 is only known as a disease in Zea mays, but the Hm1 family of genes throughout the grass family. Sindhu and colleagues silenced the corresponding gene in barley. This resulted in barley that was susceptible to CCR1. The fungus is able to invade susceptible grasses through the production of Helminthosporium carbonum* (HC) toxin. The ability of Hm1 and related genes to resist CCR1 comes from an enzyme known as HC-toxin reductase (HCTR), which detoxifies HCTR.