The involvement of aquaglyceroporins in transport of boron in barley roots.
Boron (B) enters cells as the uncharged boric acid, a small neutral molecule with sufficient lipid solubility to cross cell membranes without the aid of transport proteins. The extent to which the observed uptake rates for B in plants can be explained by this simple physical process was examined by applying treatments expected to inhibit the membrane transporters most likely to be involved in B transport. These experiments established that at least 50% of B uptake could be facilitated by transporters. The B transport characteristics of two barley aquaglyceroporins, HvPIP1;3 and HvPIP1;4, were investigated using yeast complementation assays. Expression of both genes in yeast resulted in increased B sensitivity. Transport assays in yeast confirmed that HvPIP1;3 and HvPIP1;4 are both capable of transporting B. The physiological role of these HvPIP1 genes in B transport is uncertain since their expression was not responsive to B nutritional status, and they continued to be expressed under toxicity conditions.
Fitzpatrick
Kate L
KL
School of Earth and Environmental Sciences, University of Adelaide, Adelaide, Australia. kate.fitzpatrick@adelaide.edu.au
Reid
Rob J
RJ
D051397:Aquaglyceroporins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D001895:Boron / Q000378:metabolism*; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D001467:Hordeum / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism*; D018749:RNA, Plant / Q000235:genetics; D015003:Yeasts / Q000235:genetics / Q000378:metabolism
D051397:Aquaglyceroporins; D010940:Plant Proteins; D018749:RNA, Plant; D001895:Boron