Comparative Transcriptomic Analysis of Root Cadmium Responses in Two Chinese Rice Cultivars Yuzhenxiang and Xiangwanxian 12

Shangdu Zhang,Huidan Jiang,Xiang Wu,Bangzhi Shi,Leliang Zhou,Lianyang Bai,Zhenliang Luo,Wenneng Wu

doi:10.1155/2021/2166775

Abstract

Cadmium (Cd) pollution in paddy soil is an increasingly serious issue in rice production. It has been reported that there is a higher or lower grain Cd accumulation in the rice cultivars Yuzhenxiang (YZX) or Xiangwanxian 12 (XWX), respectively. To better manage the Cd pollution problem, the genes that might play vital roles in governing the difference in root Cd responses between these two rice cultivars were examined. In this study, the results of RNA sequencing (RNA-seq) showed that there were 341 and 161 differentially expressed genes in the roots of YZX and XWX after Cd exposure, respectively. Among these genes, 7 genes, such as Os06g0196300 (OsJ_019618), Os07g0570700 (OsJ_24808), ADI1, GDCSH, HSFB2C, PEX11-4, and CLPB1, possessed higher degree nodes with each other, through interaction analysis by the STRING (search tool for the retrieval of interacting genes/proteins) software, suggesting that they might play vital roles in Cd response. Based on GO enrichment analysis, 41 differently expressed genes after Cd treatment in YZX or XWX were identified to be related to Cd response. Through comparative transcriptomic analysis, 257 genes might be associated with the root Cd response difference between YZX and XWX. Furthermore, we supposed that ADI1, CFBP1, PEX11-4, OsJ_019618, OsJ_24808, GDCSH, CLPB1, LAC6, and WNK3 might be implicated in Cd response based on the combined analysis of RT-qPCR, interaction, and GO annotation analysis. In conclusion, the numerous genes that might be related to Cd stress response and root Cd response difference between YZX and XWX at the booting stage may be of benefit for the development of rice varieties with low Cd consumption.

Highlights

Rice (Oryza sativa L.) is the primary source of calorie intake in plenty of countries, including China, and the staple food of over half of the world’s population [1, 2]
We further examined the expression patterns of 10 genes (ferredoxin-1 (ADI1), fructose-1, 6-bisphosphatase (CFBP1), glycine cleavage system H protein (GDCSH), laccase-6 (LAC6), peroxiredoxin Q (Os06g0196300), ribosome-recycling factor (Os07g0570700), peroxisomal membrane protein 11–4 (PEX11-4), probable serine/threonineprotein kinase WNK3, chaperone protein CLPB1, and heat stress transcription factor B-2c (HSFB2C)) by real-time quantitative reverse transcription PCR (RT-qPCR) assay and filtered some key genes related to Cd stimulation based on RNA sequencing (RNA-seq)/RT-qPCR/interaction/GO enrichment/ GO annotation analysis together with previous study outcomes
We supposed that the difference in grain Cd accumulation in these two rice cultivars might be caused by the discrepancy of root Cd absorptive ability

Summary

Introduction

Rice (Oryza sativa L.) is the primary source of calorie intake in plenty of countries, including China, and the staple food of over half of the world’s population [1, 2]. To meet the food demand of increasing world populations, it is imperative to improve the rice yield [3]. Cd is readily absorbed by rice plants and transferred to food chains [8]. It is often accumulated in rice grains and human bodies due to its long half-life of up to 25–30 years [8, 9]. To reduce the potential harm of Cd on human health, it is imperative to screen out the genes that play vital roles in Cd response in rice plants [7]

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Discussion

Conclusion