The Arabidopsis ribonuclease gene RNS1 is tightly controlled in response to phosphate limitation

• Published in: The Plant journal : for cell and molecular biology Vol. 6; no. 5; pp. 673 - 685
• Main Authors: Bariola, Pauline A., Howard, Christie J., Taylor, Crispin B., Verburg, Michael T., Jaglan, Vanita D., Green, Pamela J.
• Format: Journal Article
• Language: English
• Published: Osney Mead, Oxford OX2 0EL, UK Blackwell Science Ltd 01.11.1994; Blackwell Science
• Subjects: Amino Acid Sequence; Arabidopsis; Arabidopsis - enzymology; Arabidopsis - growth & development; Base Sequence; Biological and medical sciences; DNA, Plant; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Plant; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Phosphates - metabolism; Plant physiology and development; Ribonucleases - genetics; Ribonucleases - metabolism; Senescence and abscission; Sequence Homology, Amino Acid; Vegetative apparatus, growth and morphogenesis. Senescence; Water and solutes. Absorption, translocation and permeability; Phosphates; Senescence; Nucleotide sequence; Enzyme; Induction; Deficiency; Ribonuclease; Gene expression; Arabidopsis thaliana; Signal transduction; Cruciferae; Dicotyledones; Angiospermae; Spermatophyta; Experimental plant
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1046/j.1365-313X.1994.6050673.x

Summary Two stimuli that have been associated with nutrient remobilization in plants are phosphate (PI) starvation and senescence. Little is known about how the nutrient remobilization machinery is induced at the molecular level, but in the case of Pi starvation, ribonucleases are considered to play important roles in the remobilization process. Here, the control of two closely related ribonuclease genes of Arabidopsis, RNS1 and RNS3 is investigated. The RNS1 gene is sharply induced during starvation for Pi, an effect specific among the major macronutrients, whereas RNS3 transcript levels remain relatively constant. RNS1 and RNS3 produced in yeast co‐migrate with Arabidopsis ribonuclease activities that exhibit the same induction properties as the transcripts in both wild‐type plants and the pho1 mutant, which is defective in xylem loading of Pi. In contrast to what occurs during Pi starvation, both RNS1 and RNS3 are modestly induced during senescence, indicating that the two stimuli could trigger different signal transduction pathways. The characterization of RNS1, in particular, provides an important first step towards elucidating the mechanisms by which plants sense and respond to Pi limitation, a prominent condition in many soil types.