Publications by authors named "Jonathan R Howarth"

A sulphate deficiency-induced gene, sdi1, has been identified by cDNA-amplified fragment length polymorphism (AFLP) analysis utilizing field-grown, nutrient-deficient wheat (Triticum aestivum var. Hereward). The expression of sdi1 was specifically induced in leaf and root tissues in response to sulphate deficiency, but was not induced by nitrogen, phosphorus, potassium or magnesium deficiency.

View Article and Find Full Text PDF

Increasing demands for productivity together with environmental concerns about fertilizer use dictate that the future sustainability of agricultural systems will depend on improving fertilizer use efficiency. Characterization of the biological processes responsible for efficient fertilizer use will provide tools for crop improvement under reduced inputs. Transcriptomic and metabolomic approaches were used to study the impact of nitrogen (N) and sulphur (S) deficiency on N and S remobilization from senescing canopy tissues during grain filling in winter wheat (Triticum aestivum).

View Article and Find Full Text PDF
Article Synopsis
  • Researchers cloned two sulfate transporters, LeST1-1 and LeST1-2, from tomato plants and found they share 76% amino acid identity and belong to a high-affinity group of sulfate transporters.
  • Both transporters demonstrated a high affinity for sulfate, with Km values around 11.5 µM and 9.8 µM, which is consistent with other known Group-1 sulfate transporters.
  • LeST1-1 is mainly expressed in tomato root tissues while LeST1-2 is present in roots, leaves, and stems, showing increased expression due to sulfate deficiency and in response to a pathogen infection.
View Article and Find Full Text PDF

Expression of the serine acetyltransferase (SAT) gene family from Arabidopsis thaliana was investigated in response to treatment with the heavy metal cadmium (Cd). A fourth member of the SAT gene family, Sat-106, was also cloned and the complete SAT gene family from A. thaliana is discussed.

View Article and Find Full Text PDF

We have previously identified an ecotype of the hyperaccumulator Thlaspi caerulescens (Ganges), which is far superior to other ecotypes (including Prayon) in Cd uptake. In this study, we investigated the effect of Fe status on the uptake of Cd and Zn in the Ganges and Prayon ecotypes, and the kinetics of Cd and Zn influx using radioisotopes. Furthermore, the T.

View Article and Find Full Text PDF