Identification of F3H, Major Secondary Metabolite-Related Gene That Confers Resistance against Whitebacked Planthopper through QTL Mapping in Rice.

Eun-Gyeong Kim,Kyung-Min Kim,Sopheap Yun,Jae-Ryoung Park

doi:10.3390/plants10010081

Abstract

Whitebacked planthopper (WBPH) is a pest that causes serious damage to rice in Asian countries with a mild climate. WBPH causes severely rice yield losses and grain poor quality each year so needs biological control. Plants resist biotic and abiotic stress using expressing variety genes, such as kinase, phytohormones, transcription factors, and especially secondary metabolites. In this research, quantitative trait locus (QTL) mapping was performed by assigning the WBPH resistance score in the Cheongcheong/Nagdong doubled haploid (CNDH) line in 2018 and 2019. The RM280-RM6909 on chromosome 4 was detected as a duplicate in 2018, 2019, and derived from Cheongcheong. This region includes cell function, kinase, signaling, transcription factors, and secondary metabolites that protect plants from the stress of WBPH. The RM280-RM6909 on chromosome 4 contains candidate genes that are similar to the flavanone 3-hydroxylase (F3H) of rice. The F3H are homologous genes, which play an important role in biosynthesis defending against biotic stress in plants. After WBPH inoculation, the relative expression level of F3H was higher in resistant line than in a susceptible line. The newly identified WBPH resistance gene F3H by QTL mapping can be used for the breeding of rice cultivars that are resistant against WBPH.

Highlights

Whitebacked planthoppers (WBPH, Sogatella furcifera) cause serious damage to rice from long-distance migratory pests that exist in rice cultivation areas around the world, including South Korea, and cause enormous economic losses due to reduced production.Rice is one of the world’s three largest crops and, including South Korea, is the most popular crop that two-thirds of the world’s population consumes in the main meal [1].in the fields where rice is bred, many pests that damage rice is distributed.In particular, WBPH acts as a vector for southern rice black-streaked dwarf virus (SRBSDV)and is the most destructive rice pest [2] that causes various damages such as wilting, blight, and lodging of rice [3,4]
We investigated candidate genes associated with WBPH resistance by selecting RM280RM6909 on chromosome 4, which was detected in duplicate as a result of quantitative trait locus (QTL) mapping associated with WBPH resistance in 2018 and 2019
Expression levels of flavanone 3-hydroxylase (F3H) showed a significant difference between the resistant and susceptible line 4 h after WBPH inoculation (p = 0.01). These results proved that F3H identified in QTL mapping using the WBPH resistance score is precisely resistant to WBPH

Summary

Introduction

Whitebacked planthoppers (WBPH, Sogatella furcifera) cause serious damage to rice from long-distance migratory pests that exist in rice cultivation areas around the world, including South Korea, and cause enormous economic losses due to reduced production.Rice is one of the world’s three largest crops and, including South Korea, is the most popular crop that two-thirds of the world’s population consumes in the main meal [1].in the fields where rice is bred, many pests that damage rice is distributed.In particular, WBPH acts as a vector for southern rice black-streaked dwarf virus (SRBSDV)and is the most destructive rice pest [2] that causes various damages such as wilting, blight, and lodging of rice [3,4]. Whitebacked planthoppers (WBPH, Sogatella furcifera) cause serious damage to rice from long-distance migratory pests that exist in rice cultivation areas around the world, including South Korea, and cause enormous economic losses due to reduced production. Rice is one of the world’s three largest crops and, including South Korea, is the most popular crop that two-thirds of the world’s population consumes in the main meal [1]. WBPH is a flying pest that arrives in South Korea from late June to July every year in Southern China and Southeast Asia [5]. The amount of WBPH flying is more than 10 times higher than that of brown planthopper (BPH), and the largest WBPH time of occurrence in South Korea is from the end of July to the beginning of August, and the injury symptom is shown after the end of August [6].

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