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Hemorrhage is one of the most prominent manifestations produced by the parenteral administration of various snake venoms especially of Habu (Mitsuhashi et al., 1959; Ohsaka et al., 1961) and other species of Crotalidae (Fidler et al., 1940; Taube et al., 1937). In order to study the principle(s) responsible for hemorrhage caused by snake venom, a quantitative method for the determination of hemorrhagic activity is required. Up to date, however, few attempts have been made to establish the quantitative estima tion of hemorrhagic activity of snake venom. Minton (1956) and Mitsuhashi et al. (1959) tried to estimate the hemorrhagic activity but the results they obtained were not repro ducible in our hands. The present authors proposed a new method, which consists of the following procedures; (1) intracutaneous injection of venom into the depilated back skin of rabbits; (2) accurate measurement of the size of hemorrhagic spot carried out from the inside of the removed skin; (3) application of the parallel line assay method for the estimation. By this method it was possible to study the relationships of hemorrhagic activity to proteolytic and other pathological activities of Habu venom (Ohsaka et al., 1960, 1961). In this paper, details of the new method will be presented. MATERIALS AND METHODS Snake venom: The work to be reported here dealt with the venom from a species of Trimeresurus flavoviridis (Habu).* Each pool of the crude venom was dried, powdered and then stored at room temperature until used. These preparations, dissolved in M/30 phosphate buffered saline (pH

Salinity stress enhances sugar accumulation in tomato (Solanum lycopersicum) fruits. To elucidate the mechanisms underlying this phenomenon, the transport of carbohydrates into tomato fruits and the regulation of starch synthesis during fruit development in tomato plants cv. ‘Micro-Tom’ exposed to high levels of salinity stress were examined. Growth with 160 mM NaCl doubled starch accumulation in tomato fruits compared to control plants during the early stages of development, and soluble sugars increased as the fruit matured. Tracer analysis with 13C confirmed that elevated carbohydrate accumulation in fruits exposed to salinity stress was confined to the early development stages and did not occur after ripening. Salinity stress also up-regulated sucrose transporter expression in source leaves and increased activity of ADP-glucose pyrophosphorylase (AGPase) in fruits during the early development stages. The results indicate that salinity stress enhanced carbohydrate accumulation as starch during the early development stages and it is responsible for the increase in soluble sugars in ripe fruit. Quantitative RT-PCR analyses of salinity-stressed plants showed that the AGPase-encoding genes, AgpL1 and AgpS1 were up-regulated in developing fruits, and AgpL1 was obviously up-regulated by sugar at the transcriptional level but not by abscisic acid and osmotic stress. These results indicate AgpL1 and AgpS1 are involved in the promotion of starch biosynthesis under the salinity stress in ABA- and osmotic stress-independent manners. These two genes are differentially regulated at the transcriptional level, and AgpL1 is suggested to play a regulatory role in this event.

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