We screened the pharmacological effects of a 50% ethanol extract of Yacon tubers and leaves on spermatogenesis in rats. As a result, we found that Yacon tuber extracts increased sperm number and serum testosterone level in rats. It has been reported that the crude extract of Yacon tubers and leaves contain phenolic acids, such as, chlorogenic acid, ferulic acid and caffeic acid by HPLC/MS analy...

Modification of tuber carbohydrate metabolism by the tuber-specific expression of a yeast invertase targeted to the cytosol or apoplast has previously been demonstrated to have diverse effects on tuber growth and metabolism. In the current study, we generated plants exhibiting tuber-specific expression of the same enzyme targeted to the vacuole. Enzymatic analysis of the carbohydrate levels of ...

To define plant 'nutritional quality' for aphids, the causal basis of the variation in aphid performance between host plants of different developmental ages was explored using the aphids Myzus persicae and Macrosiphum euphorbiae on potato plants (Solanum tuberosum). Both aphid species performed better on developmentally young ('pre-tuber-filling') plants than on mature ('tuber-filling') plants....

3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMGR, EC1.1.1.34), the key enzyme in isoprenoid biosynthesis, was purified from microsomes of potato tuber tissue, and a polyclonal antibody and two monoclonal antibodies against the purified enzyme were prepared. HMGR protein content was measured by immunotitration and radioimmunoassay using these antibodies. HMGR activity was very low in the fr...

Dormancy is one aspect of tuber physiological age that begins with potato tuber initiation. During dormancy, biochemical and physiological processes do occur but they do not trigger immediate morphological changes, yet these processes are relevant for the number of sprouts produced after breaking of the dormancy and for the growth vigour of the seed tuber. This review article reports that dorma...

BACKGROUND Since the creation of "Golden Rice", biofortification of plant-derived foods is a promising strategy for the alleviation of nutritional deficiencies. Potato is the most important staple food for mankind after the cereals rice, wheat and maize, and is extremely poor in provitamin A carotenoids. METHODOLOGY We transformed potato with a mini-pathway of bacterial origin, driving the sy...

Venom neutralizing activity of crude root extract of Corallocarpus epigaeus was determined by in vivo procedure recommended by WHO. Neutralization assays for antivenom is necessary to replace the in vitro neutralization assay. Albino mice were used to estimate venom neutralizing activity of tuber extract. Corallocarpus epigaues tuber extract preparations exhibit immunomodulatory properties. Thi...

Our objective was to define sensitive morphological indicators that could be used to discriminate between drought sensitive and drought tolerant potato cultivars before final tuber yield is reached. A total of six potato cultivars contrasting for drought tolerance and earliness were subjected to three levels of water supply in two field trials in 1995 and 1996. We examined which parameter among...