Mapping QTLs and gene validation studies for Mg2+ uptake and translocation using a MAGIC population in rice

Shuai Zhi; Wenli Zou; Jinyan Li; Lijun Meng; Jindong Liu; Jingguang Chen; Guoyou Ye

doi:10.3389/fpls.2023.1131064

Mapping QTLs and gene validation studies for Mg²⁺ uptake and translocation using a MAGIC population in rice

Front Plant Sci. 2023 Feb 23:14:1131064. doi: 10.3389/fpls.2023.1131064. eCollection 2023.

Authors

Shuai Zhi^{1

2}, Wenli Zou², Jinyan Li¹, Lijun Meng^{2

3}, Jindong Liu², Jingguang Chen^{1

2}, Guoyou Ye^{2

4}

Affiliations

¹ School of Agriculture, Sun Yat-sen University, Shenzhen, China.
² CAAS-IRRI Joint Laboratory for Genomics-Assisted Germplasm Enhancement, Agricultural Genomics Institute in Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China.
³ Kunpeng Institute of Modern Agriculture at Foshan, Foshan, China.
⁴ Rice Breeding Innovations Platform, International Rice Research Institute, Metro Manila, Philippines.

Abstract

Magnesium (Mg) is an essential element for plant growth and development. Rice is an important food crop in the world, but there are few studies on the uptake and translocation of Mg²⁺ in rice. We used a multi-parent advanced generation inter-cross (MAGIC) population constructed using four parental lines and genotyped by a 55 K rice SNP array for association analysis to locate QTLs related to Mg²⁺ uptake and translocation in rice at the seedling stage. Four QTLs (qRMg1, qRMg2, qRMg7 and qRMg8) were detected for the root Mg²⁺ concentration, which explained 11.45-13.08% of the phenotypic variation. The Mg²⁺ transporter gene, OsMGT1, was within the region of qRMg1. Three QTLs (qSMg3, qSMg7 and qSMg10) were detected for the shoot Mg²⁺ concentration, which explained 4.30-5.46% of the phenotypic variation. Two QTLs (qTrMg3 and qTrMg8) were found to affect the translocation of Mg²⁺ from the roots to the shoots, and explained 10.91% and 9.63% of phenotypic variation. qSMg3 and qTrMg3 might be the same, since they are very close to each other on chromosome 3. Analysis of candidate genes in the region of qSMg3 and qTrMg3 through qRT-PCR, complementation assay in the yeast Mg²⁺ transport-defective mutant CM66, and sequence analysis of the parental lines suggested that LOC_Os03g04360 may play important roles in Mg²⁺ uptake, translocation and accumulation in rice. Overexpression of LOC_Os03g04360 can significantly increase the Mg²⁺ concentration in rice seedlings, especially under the condition of low Mg²⁺ supply.

Keywords: MAGIC population; Mg2+ translocation; Mg2+ uptake; association analysis; quantitative trait loci (QTL); rice.

Grants and funding

This research was financially supported by the National Natural Science Foundation of China (31902103), the Guangdong Basic and Applied Basic Research Foundation (2022A1515012381), the Young Elite Scientists Sponsorship Program by CAST (2020QNRC001) and the Shenzhen Science and Technology Program (JCYJ20210324124409027 and JCYJ20200109150650397).