The STT3a subunit isoform of the Arabidopsis oligosaccharyltransferase controls adaptive responses to salt/osmotic stress. Academic Article uri icon


  • Arabidopsis stt3a-1 and stt3a-2 mutations cause NaCl/osmotic sensitivity that is characterized by reduced cell division in the root meristem. Sequence comparison of the STT3a gene identified a yeast ortholog, STT3, which encodes an essential subunit of the oligosaccharyltransferase complex that is involved in protein N-glycosylation. NaCl induces the unfolded protein response in the endoplasmic reticulum (ER) and cell cycle arrest in root tip cells of stt3a seedlings, as determined by expression profiling of ER stress-responsive chaperone (BiP-GUS) and cell division (CycB1;1-GUS) genes, respectively. Together, these results indicate that plant salt stress adaptation involves ER stress signal regulation of cell cycle progression. Interestingly, a mutation (stt3b-1) in another Arabidopsis STT3 isogene (STT3b) does not cause NaCl sensitivity. However, the stt3a-1 stt3b-1 double mutation is gametophytic lethal. Apparently, STT3a and STT3b have overlapping and essential functions in plant growth and developmental processes, but the pivotal and specific protein glycosylation that is a necessary for recovery from the unfolded protein response and for cell cycle progression during salt/osmotic stress recovery is associated uniquely with the function of the STT3a isoform.

published proceedings

  • Plant Cell

altmetric score

  • 3

author list (cited authors)

  • Koiwa, H., Li, F., McCully, M. G., Mendoza, I., Koizumi, N., Manabe, Y., ... Hasegawa, P. M.

citation count

  • 167

complete list of authors

  • Koiwa, Hisashi||Li, Fang||McCully, Michael G||Mendoza, Imelda||Koizumi, Nozomu||Manabe, Yuzuki||Nakagawa, Yuko||Zhu, Jianhua||Rus, Ana||Pardo, José M||Bressan, Ray A||Hasegawa, Paul M

publication date

  • October 2003