NUCLEOPORIN85 is required for calcium spiking, fungal and bacterial symbioses, and seed production in Lotus japonicus.
In Lotus japonicus, seven genetic loci have been identified thus far as components of a common symbiosis (Sym) pathway shared by rhizobia and arbuscular mycorrhizal fungi. We characterized the nup85 mutants (nup85-1, -2, and -3) required for both symbioses and cloned the corresponding gene. When inoculated with Glomus intraradices, the hyphae managed to enter between epidermal cells, but they were unable to penetrate the cortical cell layer. The nup85-2 mutation conferred a weak and temperature-sensitive symbiotic phenotype, which resulted in low arbuscule formation at 22 degrees C but allowed significantly higher arbuscule formation in plant cortical cells at 18 degrees C. On the other hand, the nup85 mutants either did not form nodules or formed few nodules. When treated with Nod factor of Mesorhizobium loti, nup85 roots showed a high degree of root hair branching but failed to induce calcium spiking. In seedlings grown under uninoculated conditions supplied with nitrate, nup85 did not arrest plant growth but significantly reduced seed production. NUP85 encodes a putative nucleoporin with extensive similarity to vertebrate NUP85. Together with symbiotic nucleoporin NUP133, L. japonicus NUP85 might be part of a specific nuclear pore subcomplex that is crucial for fungal and rhizobial colonization and seed production.
Saito
Katsuharu
K
Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama 332-0012, Japan.
Yoshikawa
Makoto
M
Yano
Koji
K
Miwa
Hiroki
H
Uchida
Hisaki
H
Asamizu
Erika
E
Sato
Shusei
S
Tabata
Satoshi
S
Imaizumi-Anraku
Haruko
H
Umehara
Yosuke
Y
Kouchi
Hiroshi
H
Murooka
Yoshikatsu
Y
Szczyglowski
Krzysztof
K
Downie
J Allan
JA
Parniske
Martin
M
Hayashi
Makoto
M
Kawaguchi
Masayoshi
M
D000483:Alleles; D000595:Amino Acid Sequence; D001419:Bacteria; D002118:Calcium / Q000378:metabolism*; D005658:Fungi / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D006801:Humans; D000070116:Lotus / Q000033:anatomy & histology / Q000235:genetics / Q000382:microbiology / Q000502:physiology; D008969:Molecular Sequence Data; D028861:Nuclear Pore Complex Proteins / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000382:microbiology / Q000648:ultrastructure; D012639:Seeds / Q000378:metabolism*; D016415:Sequence Alignment; D013559:Symbiosis
D028861:Nuclear Pore Complex Proteins; D010940:Plant Proteins; D002118:Calcium