Fine Mapping and Candidate-Gene Analysis of an open glume multi-pistil 3 (mp3) in Rice (Oryza sativa L.)

Abstract

The rice mutant mp3 was derived from an indica–japonica cross between Rejing35 and XieqingzaoB, producing an inconstant number of pistils ranging from one to four pistils in a floret at heading stage, which also developed an open-glume with one or two seeds and twin seedlings at mature and seedling stage. Several altered characteristics, including filling grain panicle–1 (62.90), grain-setting rate (60.48%) and grain yield plant–1 (13.42 g), decreased but an increase in 1000-grain weight (36.87 g) was observed. Genetic analysis revealed that the mp3 mutant phenotype was controlled by a single recessive gene. Using a chromosome walking strategy in the F2 population of 02428/mp3, the mp3 gene was fine mapped between L3-135 and RM7576, with a physical distance of 30.617 kb on rice chromosome 3. Four candidate genes were found in this region referred to the rice genome annotations. LOC_Os03g11614/OsMADS1 corresponded with the mutant mp3 phenotype. Sequencing showed no sequence alterations in the coding and promoter sequence of the LOC_Os03g11614/OsMADS1 of mp3. The mp3 gene may be an allelic gene with three previously reported genes but controlled different mutant floral organ phenotypes in rice. Therefore, this mp3 gene provided a novel perspective on the biological function of OsMADS1 in the development of rice floral organ.

Analysis of Altered Flowering Related Genes in a Multi-Silique Rapeseed (Brassica napus L.) Line zws-ms Based on Combination of Genome, Transcriptome and Proteome Data

“…The MADS-box genes are comprehensively found in various plant species, and they are responsible for control the development of inflorescence meristem, floral meristem, and floral organ identity [34]. OsMADS1 [17], a MADS gene in rice, was found responsible for the recessive multi-pistil trait in mutant mp3. Besides, PavFUL, a MADS-box gene in sweet cherry that is homologous to FRUITFUL (FUL, also known as AGL8) in Arabidopsis, its seasonal expression level was found highly related to multi-pistil formation; furthermore, when overexpressed in Arabidopsis, it also caused in multi-silique phenomenon [34].…”

“…In fact, many multi-pistil traits in various plants attributes to crossing. For instance, mp3, a rice mutant displaying an inconstant number of pistils ranging from one to four pistils in a floret, was obtained from a cross of indica-and japonica-rices [17]. Thus, it is assumed that crossing between species or subspecies is a way to generate the abnormal floral structure.…”

“…It is undeniable that the multi-pistil formation in plants is more complex than we expected. Besides the genetic mutation [40] or crossing [17], heterogeneous cytoplasm [8,41] or environmental factors like temperature [15] also influence this trait.…”

“…To date, we have known that multi-pistil underlying genes belong to several types: (1) FLORAL ORGAN NUMBER 1 (FON1), ortholog of CLAVATA1 (CLV1) in Arabidopsis, encodes a leucine-rich repeat receptor-like kinase (LRR-RLK) [14,17]. (2) FON2, also known as FON4 [18,19], belongs to the CLE family.…”

“…These multi-pistil-similar traits from various crops were not only morphologically described, but some of the causal genes have been mapped to chromosomal regions or even cloned, such as FLORAL ORGAN NUMBER1 (FON1) [14,17], FON4 (also known as FON2) [18,19], LATERAL FLORET1 (LF1) [20] in rice and PaMADS3, PaMADS4 and PaMADS5 in sweet cherry [15]. However, so far, few underlying genes have been precisely cloned and functionally validated in Brassica plants.…”