The G123 rice mutant, carrying a mutation in SE13, presents alterations in the expression patterns of photosynthetic and major flowering regulatory genes

Abstract

Day length is a determinant of flowering time in rice. Phytochromes participate in flowering regulation by measuring the number of daylight hours to which the plant is exposed. Here we describe G123, a rice mutant generated by irradiation, which displays insensitivity to the photoperiod and early flowering under both long day and short day conditions. To detect the mutation responsible for the early flowering phenotype exhibited by G123, we generated an F 2 population, derived from crossing with the wild-type, and used a pipeline to detect genomic structural variation, initially developed for human genomes. We detected a deletion in the G123 genome that affects the PHOTOPERIOD SENSITIVITY13 (SE13) gene, which encodes a phytochromobilin synthase, an enzyme implicated in phytochrome chromophore biosynthesis. The transcriptomic analysis, performed by RNA-seq, in the G123 plants indicated an alteration in photosynthesis and other processes related to response to light. The expression patterns of the main flowering regulatory genes, such as Ghd7, Ghd8 and PRR37, were altered in the plants grown under both long day and short day conditions. These findings indicate that phytochromes are also involved in the regulation of these genes under short day conditions, and extend the role of phytochromes in flowering regulation in rice.

A Mutation in CsHY2 Encoding a Phytochromobilin (PΦB) Synthase Leads to an Elongated Hypocotyl 1(elh1) Phenotype in Cucumber (Cucumis sativus L.)

“…For example, all reported mutants with mutations in the FBR domain, such as Arabidopsis hy2-1, hy2-104, hy2-101, and hy2-103 (Kohchi et al 2001), tomato au, au ls and au w (Terry and Kendrick. 1996;Muramoto et al 2005;Wu et al 2020), maize elm1, and rice se13 (Sawers et al 2002;Sawers et al 2004;Saito et al 2011;Reig-Valiente et al 2020), display common defective phenotypes with long hypocotyl and yellow green leaves as in the cucumber elh1 mutant identi ed herein that also carried an amino acid substitution (D104N) in the FBR domain (Figs. 1A-1D, 3D, S1; Supplemental le 3).…”

“…The FBR domain is crucial for catalytic performance, and mutations in the domain would lead to loss-of-function of HY2 and thus severely de cient in photoreversible phys (Terry and Kendrick. 1996;Kohchi et al 2001;Sawers et al 2002;Sawers et al 2004;Muramoto et al 2005;Wu et al 2020;Reig-Valiente et al 2020). For example, all reported mutants with mutations in the FBR domain, such as Arabidopsis hy2-1, hy2-104, hy2-101, and hy2-103 (Kohchi et al 2001), tomato au, au ls and au w (Terry and Kendrick.…”

A mutation in CsHY2 encoding a phytochromobilin (PΦB) synthase leads to an elongated hypocotyl 1(elh1) phenotype in cucumber (Cucumis sativus L.)

“…The FBR domain is crucial for catalytic performance, and mutations in the domain would lead to loss-of-function of HY2 and thus severely de cient in photoreversible phys (Terry and Kendrick. 1996;Kohchi et al 2001;Sawers et al 2002;Sawers et al 2004;Muramoto et al 2005;Wu et al 2020;Reig-Valiente et al 2020). For example, all reported mutants with mutations in the FBR domain, such as Arabidopsis hy2-1, hy2-104, hy2-101, and hy2-103 (Kohchi et al 2001), tomato au, au ls and au w (Terry and Kendrick.…”

Genetic analysis of rice seedling traits related to machine transplanting under different seeding densities

“…LOC_Os05g28500, a pentatricopeptide-repeat protein (PPR), speci cally expressed in rice seedling and 20-day-old leaves, induced under the biotic and abiotic stresses [73]. LOC_Os05g28730, encoding a C3HC4-type zinc nger domain containing protein [74] and LOC_Os05g28740 (universal stress protein) [75] were both reported to involved in abiotic stress response. Detailed functional analysis of these genomic regions and candidate genes through construction and evaluation of near-isogenic lines would further improve the understanding of genetic basis of seedling traits related to seeding densities as well as putting into practice according to variety types and cropping systems during mechanical transplanting.…”