TY - JOUR
T1 - Sphingolipids in the root play an important role in regulating the leaf ionome in Arabidopsis thaliana
AU - Chao, Dai Yin
AU - Gable, Kenneth
AU - Chen, Ming
AU - Baxter, Ivan
AU - Dietrich, Charles R.
AU - Cahoon, Edgar B.
AU - Guerinot, Mary Lou
AU - Lahner, Brett
AU - Lü, Shiyou
AU - Markham, Jonathan E.
AU - Morrissey, Joe
AU - Han, Gongshe
AU - Gupta, Sita D.
AU - Harmon, Jeffrey M.
AU - Jaworski, Jan G.
AU - Dunn, Teresa M.
AU - Salt, David E.
PY - 2011/3
Y1 - 2011/3
N2 - Sphingolipid synthesis is initiated by condensation of Ser with palmitoyl-CoA producing 3-ketodihydrosphinganine (3-KDS), which is reduced by a 3-KDS reductase to dihydrosphinganine. Ser palmitoyltransferase is essential for plant viability. Arabidopsis thaliana contains two genes (At3g06060/TSC10A and At5g19200/TSC10B) encoding proteins with significant similarity to the yeast 3-KDS reductase, Tsc10p. Heterologous expression in yeast of either Arabidopsis gene restored 3-KDS reductase activity to the yeast tsc10D mutant, confirming both as bona fide 3-KDS reductase genes. Consistent with sphingolipids having essential functions in plants, double mutant progeny lacking both genes were not recovered from crosses of single tsc10A and tsc10B mutants. Although the 3-KDS reductase genes are functionally redundant and ubiquitously expressed in Arabidopsis, 3-KDS reductase activity was reduced to 10% of wild-type levels in the loss-of-function tsc10a mutant, leading to an altered sphingolipid profile. This perturbation of sphingolipid biosynthesis in the Arabidopsis tsc10a mutant leads an altered leaf ionome, including increases in Na, K, and Rb and decreases in Mg, Ca, Fe, and Mo. Reciprocal grafting revealed that these changes in the leaf ionome are driven by the root and are associated with increases in root suberin and alterations in Fe homeostasis.
AB - Sphingolipid synthesis is initiated by condensation of Ser with palmitoyl-CoA producing 3-ketodihydrosphinganine (3-KDS), which is reduced by a 3-KDS reductase to dihydrosphinganine. Ser palmitoyltransferase is essential for plant viability. Arabidopsis thaliana contains two genes (At3g06060/TSC10A and At5g19200/TSC10B) encoding proteins with significant similarity to the yeast 3-KDS reductase, Tsc10p. Heterologous expression in yeast of either Arabidopsis gene restored 3-KDS reductase activity to the yeast tsc10D mutant, confirming both as bona fide 3-KDS reductase genes. Consistent with sphingolipids having essential functions in plants, double mutant progeny lacking both genes were not recovered from crosses of single tsc10A and tsc10B mutants. Although the 3-KDS reductase genes are functionally redundant and ubiquitously expressed in Arabidopsis, 3-KDS reductase activity was reduced to 10% of wild-type levels in the loss-of-function tsc10a mutant, leading to an altered sphingolipid profile. This perturbation of sphingolipid biosynthesis in the Arabidopsis tsc10a mutant leads an altered leaf ionome, including increases in Na, K, and Rb and decreases in Mg, Ca, Fe, and Mo. Reciprocal grafting revealed that these changes in the leaf ionome are driven by the root and are associated with increases in root suberin and alterations in Fe homeostasis.
UR - http://www.scopus.com/inward/record.url?scp=79955591442&partnerID=8YFLogxK
U2 - 10.1105/tpc.110.079095
DO - 10.1105/tpc.110.079095
M3 - Article
AN - SCOPUS:79955591442
SN - 1040-4651
VL - 23
SP - 1061
EP - 1081
JO - Plant Cell
JF - Plant Cell
IS - 3
ER -