Multiple areas investigation reveals the genes related to vascular bundles in rice

Cheng Fei,Quan Xu,Zhengjin Xu,Xin Geng

doi:10.1186/s12284-019-0278-x

Cheng Fei, Quan Xu + Show 2 more

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https://doi.org/10.1186/s12284-019-0278-x

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Journal: Rice	Publication Date: Mar 21, 2019
Citations: 15	License type: open-access

Affiliation: Rice Research Institute, Shenyang Agricultural University

Abstract

BackgroundThe vascular bundle in the panicle neck is a crucial trait in rice (Oryza sativa) production that differs between the indica and japonica subspecies. However, the effect of indica/japonica genetic background on the vascular bundles remains unknown.ResultsA series of recombinant inbred lines (RILs) derived from a cross between japonica and indica were planted in three areas. High-throughput sequencing was conducted to determine the indica pedigree percentage and for quantitative trait locus (QTL) analysis. The indica pedigree affected the number of large vascular bundles (LVBs), but not the number of small vascular bundles (SVBs). QTL analysis identified a locus (qLVB9) that was pleiotropic for both LVBs and SVBs in all three areas, and qLVB9 appeared synonymous with DENSE AND ERECT PANICLE 1 (DEP1). Using CRISPR/Cas9 gene editing and gene overexpression technology, we confirmed that the truncated dep1 allele increased the number of LVBs, and resulted in LVBs more closely associated to the indica pedigree. RNA sequencing showed that the truncated dep1 allele downregulated the AP2-like gene family. The double mutant for the DEP1 and AP2-like genes (OsAP2–39) showed decreased endogenous abscisic acid (ABA) level and insensitivity to exogenous ABA treatment, confirming that both DEP1 and OsAP2–39 are involved in the ABA response mechanism.ConclusionsThe present study showed the qLVB9/DEP1 affects LVBs, and involved in ABA signaling via regulating the AP2-like gene family. These results offer new insights into the function of qLVB9/DEP1 in rice.

Highlights

The vascular bundle in the panicle neck is a crucial trait in rice (Oryza sativa) production that differs between the indica and japonica subspecies
Characterization of the vascular bundles of the parent line and recombinant inbred lines (RILs) from three different areas To better understand the effect of the indica/japonica genetic background on vascular bundles in rice, we planted a series of 155 RILs derived from a cross between the indica variety “R99” and japonica variety “SN265” in three typical rice cultivation areas, namely Shenyang (SY) (N42°), Jiangsu (JS) (N32°), and Shenzhen (SZ) (N22°)
Vascular bundle is an important trait in rice production, and a highly significant difference was found between the two subspecies, indica and japonica

Summary

Introduction

The vascular bundle in the panicle neck is a crucial trait in rice (Oryza sativa) production that differs between the indica and japonica subspecies. The selection of source, sink, and translocation capacity play critical roles in the improvement of rice yield potential (Donald, 1968, Lafitte and Travis, 1984, Ashraf et al, 1994). The vascular bundle, that in the panicle neck, is the transport system that links the source to the sink and strongly affects the transport efficiency of photosynthetic products, mineral nutrients, and water (Peterson et al, 1982). Vascular bundles in plants play a significant role in the transportation of water, nutrients, and other substances required for biological processes (Lucas et al, 2013).

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