Sugar Regulate The Physiologyogy Of Potato Under Different Level Of Phosphorus

Inorganic phosphate (Pi) plays a pivotal role in growth and development of plants.However, the availability and mobility of phosphate are lower at natural and agriculturalecosystems. Phosphorus deficiency directly affects the quality and quantity of crops. To copewith low Pi availability, plants have evolved sophisticated developmental and metabolicadaptations to enhance Pi acquisition. Such strategies included reducing the efflux ofphosphorus and increasing acquisition of Pi from soil and increasing Pi availability frominsoluble salt complexes. Sugar have been shown to fulfill a dual role in plants, as bothmetabolites and signaling molecules. The transduction pathway of sugar signal plays animportant role in the regulation of plant responses to low phosphorus stress. Sugar signalingregulates processes, include the synthesis of starch, and stimulating growth and storage of sinktissues. Sugar-signalling networks not only involved plant responses to low P availability, butsugars also in the synthesis of anthocyanin. Potato is an important tuber crops. In the study,the sugar accumulation and regulation mechanism in potato seedling under differentphosphorus levels were investigated. The results were as follow:The seedling of potato (Solanum tuberosum L.) were used as material. The seedling wereculture MS medium (containing0.1mol/L sucrose, maltose, lactose, trehalose, glucose,fructose, galactose, sorbitol, respectively) under0.5mM and1.25mM level of Pi. Fourdifferent treatments including P+S+, P+S-, P-S+and P-S-were used in the research. Themorphological characteristics of seedling, the content of phosphorus, the content ofanthocyanin, the content of sugar, the content of starch were examined.Under the phosphorus deficiency, the fresh weight and dry weight of seedling wereincreased significantly under sucrose, maltose, lactose, trehalose, glucose and fructoserespectively. The fresh weight and dry weight were lower than the other treatment under thegalactose and sorbitol. Low level phosphorus affected the metabolic pathway of galactose andsorbitol. The present study suggested that the low level phosphorus result in decreasing drymatter accumulation n seedling of potato. The Pi content were lower than other treatmentunder sucrose, lactose, trehalose, galactose and sorbitol treatment. However, the Pi contentenhanced slightly under maltose, glucose and fructose treatment. The Pi content in roots werehigher than the other treatment in different sugar conditions under1.25mM Pi treatment.Expect for lactose and glucose treatment, the Pi content in the shoots was lower than the othertreatment. The Pi content in the shoot reached minimum by59.5%, compared to the control. The Pi content reached maximum under maltose treatment. The Pi content increased by13.6%and7.2%under sorbitol and glucose treatment, compared to control. Under1.25mMphosphorus condition, the sugars played a different role in promoting the anthocyaninsynthesis and accumulation. The content of anthocyanin were higher than control under allsugars. However, the content of anthocyanin under lactose, glucose, sorbitol, sucrose andtrehalose treatment were higher than control under0.5mM phosphorus condition. There wasno significant difference among galactose, maltose with the control. Comparing with control,the starch content of seedlings were higher than others with sucrose, maltose, lactose, glucose,fructose, galactose and sorbitol treatment under0.5mM Pi condition. The synthesis of sucrosewere increased under different sugars, compared to the control under0.5mM Pi condition.