Introgression of a functional epigenetic OsSPL14WFP allele into elite indica rice genomes greatly improved panicle traits and grain yield

Abstract

Rice yield potential has been stagnant since the Green Revolution in the late 1960s, especially in tropical rice cultivars. We evaluated the effect of two major genes that regulate grain number, Gn1a/OsCKX2 and IPA1/WFP/OsSPL14, in elite indica cultivar backgrounds. The yield-positive Gn1a-type 3 and OsSPL14WFP alleles were introgressed respectively through marker-assisted selection (MAS). The grain numbers per panicle (GNPP) were compared between the recipient allele and the donor allele groups using segregating plants in BC3F2 and BC3F3 generations. There was no significant difference in GNPP between the two Gn1a alleles, suggesting that the Gn1a-type 3 allele was not effective in indica cultivars. However, the OsSPL14WFP allele dramatically increased GNPP by 10.6–59.3% in all four different backgrounds across cropping seasons and generations, indicating that this allele provides strong genetic gain to elite indica cultivars. Eventually, five high-yielding breeding lines were bred using the OsSPL14WFP allele by MAS with a conventional breeding approach that showed increased grain yield by 28.4–83.5% (7.87–12.89 t/ha) vis-à-vis the recipient cultivars and exhibited higher yield (~64.7%) than the top-yielding check cultivar, IRRI 156 (7.82 t/ha). We demonstrated a strong possibility to increase the genetic yield potential of indica rice varieties through allele mining and its application.

Genome-Wide Characterization and Expression Profiling of Squamosa Promoter Binding Protein-Like (SBP) Transcription Factors in Wheat (Triticum aestivum L.)

“…When we compared the conserved domains of TaSBP protein sequences with DNAman 6.0, we found that a few sites in the SBP domain coding region had an amino acid substitution ( Figure 13). For example, in the first zinc-binding site, Cys(8)-Cys(25)-His(28)-Cys (30), His was replaced by Cys in TaSBP1-ALa, TaSBP1-BLa, TaSBP1-BLb, and TaSBP1-Dla. The other zinc-binding site in wheat SBPs is Cys(45)-Cys(48)-Cys(63)-His (70).…”

“…Recently, Ma et al showed that CmSBP11 was involved in the metabolism of vitamin C during muskmelon (Cucumis melo L.) ripening [28]. Another key gene, OsSPL14, was found to increase rice yields and enhance lodging resistance by controlling the number of tillers and increasing the mechanical strength of the stalks, and it has been successfully applied to breed improvement of Indica cultivars [29,30].…”

DELAYED HEADING DATE1 interacts with OsHAP5C/D, delays flowering time and enhances yield in rice

“…Thousand grain weight was determined by measuring the weight of harvested seeds that were air-dried in a glasshouse and ovendried at 50°C until they reached~14.0% moisture content. Panicle-related traits containing panicle length, primary branches number, secondary branches number and grain number per panicle were measured from main tillers of 15 plants in WT and transgenic lines respectively (Kim et al, 2018). All data are analyzed by the LSD-test.…”

Haplotype analysis of key genes governing grain yield and quality traits across 3K RG panel reveals scope for the development of tailor‐made rice with enhanced genetic gains

“…() quantified 49 panicle phenotypes in 242 tropical rice accessions with the imaging platform PANorama and identified 10 candidate genes in pathways known to regulate plant architecture. Recently, it has been demonstrated that through marker‐assisted selection (MAS) OsSPL14 WFP allele dramatically increased grain yield/panicle by 10.6–59.3% in four different genetic backgrounds (Kim et al ., ). Similarly, genome editing approach was used to alter two yield attributing genes namely, Gn1a and DEP1 .…”