Grain Zinc 7 Contributes to Zinc Deficiency Tolerance and Accumulation in Rice

doi:10.1016/j.rsci.2025.04.007

Abstract

Tang Jichun, Zhan Junhui, Liu Yuxi, Li Shuangyuyan, Lu Xiang, Meng Lijun, Ye Guoyou. Grain Zinc 7 Contributes to Zinc Deficiency Tolerance and Accumulation in Rice[J]. Rice Science, 2025, 32(5): 594-598.

Figures/Tables 1

Fig. 1. Expression patterns and phenotypic analysis of OsGZ7. A, Expression of OsGZ7 in various tissues under different zinc (Zn) levels [0.04, 0.4 (control), and 40 μmol/L]. Thirteen-day-old seedlings were transferred to 1/2 Kimura’s B solution with different Zn concentrations for 3 d before sample collection for RNA extraction and expression analysis. OsActin was used as the internal control. B, β-glucuronidase (GUS) expression of OsGZ7. Thirteen-day-old seedlings were hydroponically grown for 7 d under Zn-normal (0.4 μmol/L) and Zn-deficient (0.04 μmol/L) conditions. Blue indicates GUS activity in root (a), root tip (b), root hair (c), basal stem (d), and leaf (e). In (b)-(e), scale bars, 2 mm. C, Subcellular localization of OsGZ7 protein in rice protoplasts. The constructs of green fluorescent protein (GFP) and OsGZ7-GFP were transiently expressed in the protoplasts prepared from rice. GFP was visualized using a laser scanning microscope (LSM 980, Zeiss). Scale bars, 10 μm. D-J, Phenotype (D), shoot length (E), shoot dry weight (F), root dry weight (G), Zn content in shoot (H), Zn content in root (I), and Zn concentration in brown rice (J) of wild type (WT), nockout (KO-1 and KO-2), and overexpression (OE1 and OE2) lines of OsGZ7 under Zn-normal (0.4 μmol/L) and Zn-deficient (0.04 μmol/L) conditions after 17 d of treatment. K, Number of differentially expressed genes (DEGs) between WT and KO lines under Zn-deficient conditions. L, Venn diagram showing the number of Zn-normal and -deficiency-responsive DEGs between WT and KO lines under Zn-normal and Zn-deficient conditions. M, Kyoto Encyclopedia of Gene and Genomes (KEGG) analysis of upregulated genes under Zn-deficient conditions. In E-J, data are mean ± SD (n ≥ 3). * and ** above bars indicate significant differences between WT and each of the KO and OE lines at the 0.05 and 0.01 levels by Tukey’s HSD test.

References 35

[1]	Bouis H E, Saltzman A. 2017. Improving nutrition through biofortification: A review of evidence from HarvestPlus, 2003 through 2016. Glob Food Secur, 12: 49-58.
[2]	Broadley M R, White P J, Hammond J P, et al. 2007. Zinc in plants. New Phytol, 173(4): 677-702.
[3]	Burchi F, Fanzo J, Frison E. 2011. The role of food and nutrition system approaches in tackling hidden hunger. Int J Environ Res Public Health, 8(2): 358-373.
[4]	Cai H M, Huang S, Che J, et al. 2019. The tonoplast-localized transporter OsHMA3 plays an important role in maintaining Zn homeostasis in rice. J Exp Bot, 70(10): 2717-2725.
[5]	Calayugan M I C, Formantes A K, Amparado A, et al. 2020. Genetic analysis of agronomic traits and grain iron and zinc concentrations in a doubled haploid population of rice (Oryza sativa L.). Sci Rep, 10(1): 2283.
[6]	Cao H W, Li C, Zhang B Q, et al. 2022. A metallochaperone HIPP33 is required for rice zinc and iron homeostasis and productivity. Agronomy, 12(2): 488.
[7]	Cu S T, Warnock N I, Pasuquin J, et al. 2021. A high-resolution genome- wide association study of the grain ionome and agronomic traits in rice Oryza sativa subsp. indica. Sci Rep, 11(1): 19230.
[8]	Hacisalihoglu G, Kochian L V. 2003. How do some plants tolerate low levels of soil zinc? Mechanisms of zinc efficiency in crop plants. New Phytol, 159(2): 341-350.
[9]	Huang S, Sasaki A, Yamaji N, et al. 2020. The ZIP transporter family member OsZIP9 contributes to root zinc uptake in rice under zinc-limited conditions. Plant Physiol, 183(3): 1224-1234.
[10]	Kidwai M, Ahmad I Z, Chakrabarty D. 2020. Class III peroxidase: An indispensable enzyme for biotic/abiotic stress tolerance and a potent candidate for crop improvement. Plant Cell Rep, 39(11): 1381-1393.
[11]	Kurotani K I, Hayashi K, Hatanaka S, et al. 2015. Elevated levels of CYP94 family gene expression alleviate the jasmonate response and enhance salt tolerance in rice. Plant Cell Physiol, 56(4): 779-789.
[12]	Lee S, Jeong H J, Kim S A, et al. 2010. OsZIP5 is a plasma membrane zinc transporter in rice. Plant Mol Biol, 73(4/5): 507-517.
[13]	Lei G J, Yamaji N, Ma J F. 2021. Two metallothionein genes highly expressed in rice nodes are involved in distribution of Zn to the grain. New Phytol, 229(2): 1007-1020.
[14]	Li J M, Zhang M H, Yang L M, et al. 2021. OsADR3 increases drought stress tolerance by inducing antioxidant defense mechanisms and regulating OsGPX1 in rice (Oryza sativa L.). Crop J, 9(5): 1003-1017.
[15]	Lin W, Wang Y H, Liu X Y, et al. 2021. OsWAK112, a wall-associated kinase, negatively regulates salt stress responses by inhibiting ethylene production. Front Plant Sci, 12: 751965.
[16]	Liu X S, Feng S J, Zhang B Q, et al. 2019. OsZIP1 functions as a metal efflux transporter limiting excess zinc, copper and cadmium accumulation in rice. BMC Plant Biol, 19(1): 283.
[17]	Ludwig Y, Dueñas C Jr, Arcillas E, et al. 2024. CRISPR-mediated promoter editing of a cis-regulatory element of OsNAS2 increases Zn uptake/translocation and plant yield in rice. Front Genome Ed, 5: 1308228.
[18]	Meng F W, Yang C, Cao J D, et al. 2020. A bHLH transcription activator regulates defense signaling by nucleo-cytosolic trafficking in rice. J Integr Plant Biol, 62(10): 1552-1573.
[19]	Mu S, Yamaji N, Sasaki A, et al. 2021. A transporter for delivering zinc to the developing tiller bud and panicle in rice. Plant J, 105(3): 786-799.
[20]	Ning M, Liu S J, Deng F L, et al. 2023. A vacuolar transporter plays important roles in zinc and cadmium accumulation in rice grain. New Phytol, 239(5): 1919-1934.
[21]	Pandey B K, Verma L, Prusty A, et al. 2021. OsJAZ11 regulates phosphate starvation responses in rice. Planta, 254(1): 8.
[22]	Ramesh S A, Shin R, Eide D J, et al. 2003. Differential metal selectivity and gene expression of two zinc transporters from rice. Plant Physiol, 133(1): 126-134.
[23]	Sahid S, Roy C, Shee D, et al. 2023. ZFP37, C3H, NAC94 and bHLH148 transcription factors regulate cultivar-specific drought response by modulating r40C1 gene expression in rice. Environ Exp Bot, 214: 105480.
[24]	Sasaki A, Yamaji N, Ma J F. 2014. Overexpression of OsHMA3 enhances Cd tolerance and expression of Zn transporter genes in rice. J Exp Bot, 65(20): 6013-6021.
[25]	Singh A P, Pandey B K, Mehra P, et al. 2020. OsJAZ9 overexpression modulates jasmonic acid biosynthesis and potassium deficiency responses in rice. Plant Mol Biol, 104: 397-410.
[26]	Song C Z, Yan Y F, Rosado A, et al. 2019. ABA alleviates uptake and accumulation of zinc in grapevine (Vitis vinifera L.) by inducing expression of ZIP and detoxification-related genes. Front Plant Sci, 10: 872.
[27]	Su N N, Gong Y N, Hou X, et al. 2024. Zinc finger protein ZFP36 and pyruvate dehydrogenase kinase PDK1 function in ABA-mediated aluminum tolerance in rice. Crop J, 12(5): 1483-1495.
[28]	Tan L T, Zhu Y X, Fan T, et al. 2019. OsZIP7 functions in xylem loading in roots and inter-vascular transfer in nodes to deliver Zn/Cd to grain in rice. Biochem Biophys Res Commun, 512(1): 112-118.
[29]	Tan L T, Qu M M, Zhu Y X, et al. 2020. ZINC TRANSPORTER5 and ZINC TRANSPORTER9 function synergistically in zinc/ cadmium uptake. Plant Physiol, 183(3): 1235-1249.
[30]	Wang P T, Xu X, Tang Z, et al. 2018. OsWRKY28 regulates phosphate and arsenate accumulation, root system architecture and fertility in rice. Front Plant Sci, 9: 1330.
[31]	Wang Y W, Liao Y R, Quan C Q, et al. 2022. C2H2-type zinc finger OsZFP15 accelerates seed germination and confers salinity and drought tolerance of rice seedling through ABA catabolism. Environ Exp Bot, 199: 104873.
[32]	Wu H, Ye H Y, Yao R F, et al. 2015. OsJAZ9 acts as a transcriptional regulator in jasmonate signaling and modulates salt stress tolerance in rice. Plant Sci, 232: 1-12.
[33]	Yamaji N, Xia J X, Mitani-Ueno N, et al. 2013. Preferential delivery of zinc to developing tissues in rice is mediated by P-type heavy metal ATPase OsHMA2. Plant Physiol, 162(2): 927-939.
[34]	Zhang B Q, Liu X S, Feng S J, et al. 2020. Developing a cadmium resistant rice genotype with OsHIPP29 locus for limiting cadmium accumulation in the paddy crop. Chemosphere, 247: 125958.
[35]	Zhang M X, Zhao R R, Wang H T, et al. 2023. OsWRKY28 positively regulates salinity tolerance by directly activating OsDREB1B expression in rice. Plant Cell Rep, 42(2): 223-234.