Patcharin Songsri

Identification of peanut seed prolamins with an antifungal role by 2D-GE and drought treatment

This work revealed peanut seed prolamins likely displaying a defensive role besides the known nitrogen storage. Drought stress and proteomic approaches were used in varieties of peanuts to explore the prolamin member in association with a test against Aspergillus flavus spore germination. The stress effect was showed by aerial biomass, leaf content of malondialdehyde, and seed contamination by A. flavus. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis profiles were not informative for the antifungal polypeptides. From two-dimensional gel electrophoresis, the suspected polypeptides were those with pI 5.45–5.75 and sizes of 22.0–30.5 kDa specifically in Spanish-type peanuts. Regarding to the drought effect in most of these peanuts, the spot peak volume analysis deduced three novel prolamin-related antifungal polypeptides at pI 5.75–5.8 with 30.5, 27.5–28.5, and 22.0–22.5 kDa, which was confirmed after isoelectric purification at pH 5.60. The data could not yet conclude their correlation with resistance to drought and to seed infection by A. flavus. Graphical Abstract Antifungal peanut prolamins were related with polypeptides 1, 2, and 3 in pellet (Fig. A) not with spots 4, 5, and 6 in the supernatant (Fig. B) portion on precipitation at pH 5.60.

The Influence of Rainfall on Growth of Rubber Trees in Marginal Area of Northeast Thailand

Rubber trees grow predominately in the southern and eastern areas of Thailand, where there is the majority of rainfall. However, the rubber tree plantations extend to north and northeastern areas, with lower annual rainfall. The aim of this study was to evaluate the effect of rainfall on growth of rubber tree in northeastern areas of Thailand. The outcome of this work should be helped to indicate the optimum area for rubber tree planting in northeast. The study was undertaken using rubber tree clone RRIM600 by comparing the girth at 150 cm at the soil surface, planted in areas of differing rainfall: in Nongkhai, Chaiyaphum, Khon Kaen, Roiet and Buriram provinces. The sample of 50 trees was selected in 3 plantations per province (150 trees per province). The results found that there was no significant difference in girth of the rubber trees in all areas. However, the rubber trees planted in Nongkhai, where had highest rainfall, had highest growth. Moreover, the relationship between rainfall and growth exhibited a positive correlation, demonstrating that higher rainfall increased the girth of rubber trees.