UDP-glucose pyrophosphorylase is a common plant enzyme and plays a key role in many processes connected with carbohydrates metabolism in plant tissues. This enzyme catalyse the reversible reaction of synthesis/degradation of UDP-glucose and inorganic pyrophosphate from glucose-1-phosphate and UTP. UDP-glucose is the precursor of many carbohydrates like sucrose, starch, pectin, cellulose. The second product of UGPase activity is PPi, the alternative to ATP energy donor which supply Pi. The highest activity of UGPase was observed in cytosol.

Participation acidic phosphate phosphatases in the economy of plant cells

Acid phosphatase ( EC ) are a group of enzymes that catalyze the hydrolysis of ester variety of orthophosphate . Are commonly found in plant cells , and animal . Among the acid phosphatase distinguish several groups of enzymes with diverse substrate specificity and cellular location . Phosphatase showing a high substrate specificity have been relatively well described and their function in metabolic processes is unknown, while the role of non-specific acid phosphatase has not been fully understood.


Changes of sugar concentration often affect germination, plant growth, metabolic processes and the expression of numerous genes. Plants developed effective mechanisms of perception and trans- duction of sugar signals. Glucose, sucrose, trehalose and other sugars might serve as elicitors of plant sugar signaling. Hexokinase, sucrose and glucose transporters (and specific sugar receptors) have been proposed as components of sugar sensing machinery. Roles of G-proteins and specific serine/threonine kinases and phosphatases in sugar signal transduction in plant cell are discussed.


Plants have evolved various strategies to cope with common in nature phosphorus deficiency. Efficient inorganic phosphate (Pi) acquisition and distribution system within the plant and between cellular compartments is the most important of them. Amount and variety of transporters involved in this process indicates the complicity of Pi transport system in plants. In this work membrane transporters involved in Pi acquisition from soil (Pht1), Pi transport from root to shoot (Pht2) are characterized. Some proteins which seem to take part, or regulate this process, are also described.

Molecular basis of plant responses to phosphate deficiency

Shortage absorbed by plants inorganic phosphate (Pi) in the environment is a phenomenon often encountered . Plants adapt to the conditions of such stress by running a series of mechanisms that increase the download Pi Pi substrate and the mobilization of internal resources. The roots can secrete organic acids to the substrate , acid phosphatase , as well as , if necessary , ribonuclease . Followed by the induction of membrane conveyors Pi and intracellular phosphatases . Many plant adaptations to phosphorus deficiency is preceded by the activation (or repression ) of specific genes .

Regulatory role of sugars. Perception and signal transduction of sugars in plant cells

Sugars are not only the major end-products of photosynthesis , and transported in storage in various plant organs but also perform regulatory functions. Changes in the concentration of sugars in the tissues interact on many metabolic processes : photosynthesis , respiration , protein synthesis , nitrogen economy , inhibiting or adding to their intensity . Changes in the sugar content also affect the expression of a number of genes .

The Editorial Board
Andrzej Łukaszyk - przewodniczący, Zofia Bielańska-Osuchowska, Szczepan Biliński, Mieczysław Chorąży, Aleksander Koj, Włodzimierz Korochoda, Leszek Kuźnicki, Aleksandra Stojałowska, Lech Wojtczak

Editorial address:
Katedra i Zakład Histologii i Embriologii Uniwersytetu Medycznego w Poznaniu, ul. Święcickiego 6, 60-781 Poznań, tel. +48 61 8546453, fax. +48 61 8546440, email:

PBK Postępby biologi komórki