An Endosperm-Specific Early Nodulin-Like Gene Regulates Amylose Content in Rice

doi:10.1016/j.rsci.2025.12.001

Abstract

Zhao Dongsheng, Wu Dengfei, Chen Siyu, Fan Xiaolei, Li Qianfeng, Zhang Changquan, Liu Qiaoquan. An Endosperm-Specific Early Nodulin-Like Gene Regulates Amylose Content in Rice[J]. Rice Science, 2026, 33(2): 155-158.

Figures/Tables 1

Fig. 1. Functional analysis of AC6 gene in rice. A, Expression pattern analysis of AC6 in different rice tissues (stem, leaf, leaf sheath, and young panicle at the booting stage) and grain (5, 8, 10, 12, 14, 17, and 20 d after pollination) of transgenic rice plants using qRT-PCR. Data are mean ± SD (n = 3). Actin was selected as a reference gene. B, Histochemical assay determining the β-glucuronidase (GUS) activity in leaf, leaf sheath, inflorescence, young panicle, and grain (7, 10, 12, 14, 17, and 20 d after pollination) of transgenic rice plants. The GUS reporter gene was driven by the AC6 native promoter. Scale bars, 5 mm. C, Subcellular localization analysis of AC6 protein in tobacco leaf epidermal cells. The 35S::GFP was the control containing only the GFP coding region. The 35S::AC6-GFP constructs contained the full-length cDNA of AC6 in-frame fusion with the GFP coding region. Scale bars, 50 µm. D, Nucleotide change in AC6/LOC_Os06g04930 knockout mutants (sg6257-1-3). White boxes, black boxes, and black lines represent the untranslated regions, exons, and introns, respectively. ZH11, Zhonghua 11; gRNA, Single guide RNA; PAM, Protospacer adjacent motif. Letter in red represents the insertion, and ‘-’ represents the deletion. E-G, Plant phenotype (E), panicle phenotype (F), and grain size (G) of ZH11 and ac6 mutants (sg6257-1-3). Scale bars in E, F, and G, 5 cm, 5 cm, and 10 mm, respectively. H-K, Apparent amylose content (H), total protein content (I), total starch content (J), and soluble sugar content (K) of ZH11 and ac6 mutants (sg6257-1-3). Data are mean ± SD (n = 3). *, Significant difference at the 0.05 level by student’s t-test; ns, Not significant. L, Molecular weight distribution of starch from ZH11 and ac6 mutants (sg6257-1-3) using size exclusion chromatography. Ap1, Short amylopectin; Ap2, Long amylopectin; Am, Amylose. M, Scanning electron microscopy observation of extracted starch granules from ZH11 and ac6 mutants (sg6257-1-3). Scale bars, 15 μm. N, Grain appearance of brown rice from ZH11 and ac6 mutants (sg6257-1-3). Scale bar, 10 mm. O, Transverse section of grains (above; Scale bar, 1 mm) and morphology of starch granules (below; Scale bar, 10 μm) from ZH11 and ac6 mutants (sg6257-1-3) using scanning electron microscopy. P, Rapid viscosity analysis profiles of rice flour from ZH11 and ac6 mutants (sg6257-1-3).

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