Figure 4.

Map-Based Cloning and Expression Analysis of GOT1B.

(A) Fine mapping of the GPA4 locus. The molecular markers and the number of recombinants are shown.

(B) Gene structure and the mutation site in Os03g0209400. Os03g0209400 comprises six exons (closed boxes) and five introns (lines). ATG and TGA represent the start and stop codon, respectively. A 108-bp fragment deletion and a nucleotide substitution occurred in the coding region of Os03g0209400 in gpa4-1 and gpa4-2, respectively.

(C) to (F) The Os03g0209400 cDNA under the control of Ubiquitin promoter rescues the grain appearance (C), the storage protein composition pattern (D), and the storage protein trafficking defects ([E] and [F]) of the gpa4-2 mutant. L1 to L4 denote the grains from four independent T1 transgenic lines. Stars represent the abnormal structure with a glutelin core and a prolamin periphery in (E). Bars = 2 μm in (E) and (F).

(G) RT-qPCR assay showing that GOT1B is expressed in various wild-type tissues examined, with the highest expression in panicles before heading. S, shoot; E, endosperm; L, leaf; R, root; SL, seedling; LS, leaf sheath; P, panicle before heading. EF-1α was used as an internal control in (G) to (I). For each RNA sample, three technical replicates were performed. Values are mean ± sd.

(H) RT-qPCR assay showing that GOT1B is expressed throughout endosperm development. The expression of GOT1B in gpa4-1 was much lower compared with that in the wild type. For each RNA sample, three technical replicates were performed. Values are mean ± sd.

(I) The expression of GOT1B and its homologs in 12 DAF endosperm cells. For each RNA sample, three technical replicates were performed. Values are mean ± sd.