Untitled

Abstract

Plants respond to phosphate (Pi) deficiency through adaptive mechanisms involving several morphological, biochemical and molecular changes. In this study, we have characterized the structure and expression of a tomato (Lycopersicon esculentum L.) phosphate starvation-induced gene (TPSI1). A 3.5 kb genomic fragment containing the 474 bp TPSI1 transcript was isolated. The TPSI1 transcript contains an open reading frame of 174 nucleotides encoding a 58 amino acid polypeptide. TPSI1 is an intron-less gene and only one copy could be detected in the tomato genome. The promoter region of TPSI1 contains several conserved sequences found in phosphate starvation induced genes of yeast. The TPSI1 transcripts are rapidly induced in roots and leaves during Pi starvation. A significant increase in the TPSI1 mRNA was observed in cell cultures and roots after 3 and 12 h of Pi starvation, respectively. Induction of the TPSI1 gene appears to be a response specific to Pi starvation since it is not affected by starvation of other nutrients (nitrogen, potassium and iron). The amount of TPSI1 transcript decreased rapidly when Pi-starved tomato plants were resupplied with Pi. These results suggest that TPSI1 gene expression may be a part of the early Pi starvation response mechanism in plants.

Molecular cloning and characterization of phosphate (Pi) responsive genes in Gulf ryegrass (Lolium multiflorum L.): a Pi hyperaccumulator

“…Studies have shown variability across L. multiflorum genotypes in hyperaccumulation of Pi under both agro-climatic and controlled growth conditions (Abe et al 1999;Sharma et al 2004;Sharma and Sahi 2005). Though (Li et al 2002;Xiao et al 2006), phosphate starvation induced (Liu et al 1997;Hou et al 2005;Shin et al 2006), iron deficiency specific 1 (Wang et al 2004), and Myb transcription factor (Rubio et al 2001). This analysis validated the efficiency of the subtracted cDNA library in identifying Pi-starvation induced (PSI) genes in ryegrass.…”

Transcriptional regulation of plant phosphate transporters

“…Tomato plants were grown in an aeroponics facility as described earlier (13). The plants were subjected to various P i treatments by spraying roots at regular intervals with a fine mist of half-strength modified Hoagland's solution containing indicated amounts of P i .…”

Plant hormones and nutrient signaling

“…Moreover, only recently have molecular components within the networks mediating nutrient signaling been identified. Thanks to genetic, molecular, and biochemical studies using Arabidopsis, Medicago, tomato, rice, and the unicellular algae Chlamydomonas, several transcription factors (Colangelo and Guerinot 2004;Devaiah et al 2007a, b;Jakoby et al 2004;Ling et al 2002;Rubio et al 2001;Wykoff et al 1999Yuan et al 2008Zhang and Forde 1998;Zhou et al 2008), miRNAs (Bari et al 2006;Chiou et al 2006;Fujii et al 2005;Jones-Rhoades and Bartel 2004), riboregulators Harrison 1997, 1999;Franco-Zorrilla et al 2007;Liu et al 1997;Martín et al 2000), and other regulatory proteins, such as ubiquitin and small ubiquitin-related modifier (SUMO) pathway components, endoplasmic reticulum (ER) exit cofactors, and SPX-domain-containing proteins Bari et al 2006;Duan et al 2008;González et al 2005;Miura et al 2005;Peng et al 2007), have been characterized within these networks. Additionally, control of nutrient signaling involves different metabolites (see, for example, Coruzzi and Zhou 2001;Forde and Lea 2007;Franco-Zorrilla et al 2005;Hermans et al 2006;Kopriva 2006), reactive oxygen species (ROS; Shin and Schachtman 2004), and hormones (see for example reviews by Ashley et al 2006;Franco-Zorrilla et al 2004;Kopriva 2006;Sakakibara et al 2006;Schachtman and Shin 2007;Schmidt et al 2000;…”