Transcriptome analysis of root transporters reveals participation of multiple gene families in the response to cation stress

Abstract

SummaryPlant nutrition critically depends on the activity of membrane transporters that translocate minerals from the soil into the plant and are responsible for their intra-and intercellular distribution. Most plant membrane transporters are encoded by multigene families whose members often exhibit overlapping expression patterns and a high degree of sequence homology. Furthermore, many inorganic nutrients are transported by more than one transporter family. These considerations, coupled with a large number of so-far non-annotated putative transporter genes, hamper our progress in understanding how the activity of speci®c transporters is integrated into a response to¯uctuating conditions. We designed an oligonucleotide microarray representing 1096 Arabidopsis transporter genes and analysed the root transporter transcriptome over a 96-h period with respect to 80 mM NaCl, K starvation and Ca 2 starvation. Our data show that cation stress led to changes in transcript level of many genes across most transporter gene families. Analysis of transcriptionally modulated genes across all functional groups of transporters revealed families such as V-type ATPases and aquaporins that responded to all treatments, and families ± which included putative non-selective cation channels for the NaCl treatment and metal transporters for Ca 2 starvation conditions ± that responded to speci®c ionic environments. Several gene families including primary pumps, antiporters and aquaporins were analysed in detail with respect to the mRNA levels of different isoforms during ion stress. Cluster analysis allowed identi®cation of distinct expression pro®les, and several novel putative regulatory motifs were discovered within sets of co-expressed genes.

Relationship between water use efficiency (WUE) and production of different wheat genotypes at soil water deficit

“…What is the relationship of mineral elements (in particular, K + Na + in soils) with root signal transduction (pathways)? Much of former study showed that K + was little connected with anti-drought, but recent research and our results displayed that it was linked with wheat resistance drought [3,7,39,60,66,67,75]. What is the exact soil water stress threshold of individual wheat genotype?…”

“…Just 1 year ago, European Commission, who once kept conservative to biotechnological breeding, constructed a big project: Plants for the Future: a European vision for Plant Biotechnology towards 2025, in which much is involved in resistance drought [14]. Many advances in relation to this hot topic, including molecular mechanism of anti-drought and corresponding molecular breeding have taken place [28,33,34,39,44,47,50,53,[55][56]63,[72][73][74][75]78]. Although the obtained transgenic crops (mainly, wheat) by different types of gene technology all exhibit drought resistance to some extent, they have many shortfalls related to agronomical performance and/or development [47,49,53,62,66,68,74].…”

Changes of some anti-oxidative physiological indices under soil water deficits among 10 wheat (Triticum aestivum L.) genotypes at tillering stage

“…What is the relationship of mineral elements (in particular, K + Na + ) with root signal transduction (pathways)? Much of former study showed that K + was little connected with anti-drought, but recent research and our results displayed that it was linked with wheat resistance drought [8,22,49,46,42,55]. What is the exact soil water stress threshold of individual wheat genotype?…”

“…Drought is a complex physical-chemical process, in which many biological macromolecules and small molecules are involved, such as nucleic acids (DNA, RNA, microRNA), proteins, carbohydrates, lipids, hormones, ions, free radicals, mineral elements [3,8,12,13,18,20,22,26,31,43,49,50,55,65]. In addition, drought is also related to salt stress, cold stress, high temperature stress, acid stress, alkaline stress, pathological reactions, senescence, growth, development, cell cycle, UV-B damage, wounding, embryogenesis, flowering, signal transduction and so on [16,17,[26][27][28]36,37,[44][45][46][47][52][53][54]62].…”

The role of calcium sensor-interacting protein kinases in plant adaptation to potassium-deficiency: new answers to old questions

“…K + -uptake and its re-distribution within the plant is facilitated by a plethora of membrane transport proteins displaying an astonishing diversity with respect to their affinity and selectivity for K + , mode and direction of transport, tissue specific expression, membrane localization and regulation [2]. Microarray experiments have shown that -in contrast to transporters of other macronutrients -genes encoding K + -transporters display surprisingly little responsiveness to the external nutrient supply [3]. This observation probably reflects that because of its vital role in maintenance of cell turgor and membrane potential K + -transport has to respond very quickly to changes in the environment.…”