Wilson County Master Gardener Association

Jan. 4, 2013 — For almost 30 years, researchers have sought to identify a particular enzyme that is involved in regulating electron transport during photosynthesis. A team at Ludwig-Maximilians-Universität (LMU) in Munich has now found the missing link, which turns out to be an old acquaintance.

Photosynthesis sustains life on Earth by providing energy-rich compounds and the molecular oxygen that higher organisms depend on. The process is powered by sunlight, which is captured by “biochemical solar cells” called photosystems that are found in plants, algae and certain types of bacteria. Plants have two photosystems, PSI and PSII. Each consists of a pigment-protein complex that uses solar energy to raise electrons to a higher energy level. These are then passed along a chain of electron acceptors, and the energy released is employed for synthesis of ATP, the “coinage” used for all energy transactions in cells. [ … continue ]

Source: http://www.sciencedaily.com/releases/2013/01/130104101155.htm

Jan. 3, 2013 — Climate change poses a major challenge to humanity’s ability to feed its growing population. But a new study of sorghum, led by Stephen Kresovich and Geoff Morris of the University of South Carolina, promises to make this crop an invaluable asset in facing that challenge. Just published in the Proceedings of the National Academy of Sciences (PNAS), the paper puts genetic tools into the hands of scientists and plant breeders to help accelerate their ability to adapt sorghum to new conditions.

A hardy cereal crop that was first domesticated in the Horn of Africa some 10,000 years ago, sorghum is now cultivated worldwide, from Texas to China. Sorghum is a particularly drought-tolerant grain and an essential part of the diet for 500 million people, chiefly in sub-Saharan Africa and India. In the U.S., where it is primarily grown for livestock feed, sorghum’s climate resilience was highlighted during the devastating summer drought of 2012.

A large international effort decoded the genome of the species cultivated for food, Sorghum bicolor, which was published in the journal Nature in 2009. That genome represents the genetic accounting of a single individual of sorghum. But as individual humans have genetic differences that underlie physical differences such as eye color, so do individual plants of sorghum. The focus of the current effort was to establish the connections between gene differences and physical differences — a detailed understanding of those connections will constitute a tremendous tool for plant breeders. [ … continue ]

Source: www.sciencedaily.com/releases/2013/01/130103092016.htm

Dec. 28, 2012 — South West China, Myanmar and Northern Vietnam contain one of the oldest exposed outcrops of limestone in the world. Within this area are thousands of caves and gorges. It is only recently that botanists have sought to explore the caves for plants. This exploration is yielding many new species new to science, that are known only from these habitats.

The current study was published in the open access journal PhytoKeys.

Kew botanist and nettle expert Alex Monro says, “When my Chinese colleague Wei Yi-Gang from the Guangxi Institute of Botany first mentioned cave-dwelling plants to me, I thought that he was mis-translating a Chinese word into English. When we stepped into our first cave, Yangzi cave, I was spell-bound. It had an eerie moonscape look to it and all I could see were clumps of plants in the nettle family growing in very dark condition.”

The plants do not grow in complete darkness but do grow in extremely low light levels, deep within the entrance caverns of the caves (sometimes, in as little as 0.04% full sunlight). The British and Chinese authors have been collecting plants from the Nettle family in this limestone landscape for several years and have just published a paper describing three new species, one from a cave and another two from deep gorges. [ … continue ]

Source:  www.sciencedaily.com/releases/2012/12/121228133732.htm