Tomato CRABS CLAW paralogues interact with chromatin remodelling factors to mediate carpel development and floral determinacy

Abstract

Summary CRABS CLAW (CRC) orthologues play a crucial role in floral meristem (FM) determinacy and gynoecium formation across angiosperms, the key developmental processes for ensuring successful plant reproduction and crop production. However, the mechanisms behind CRC mediated FM termination are far from fully understood. Here, we addressed the functional characterization of tomato (Solanum lycopersicum) paralogous CRC genes. Using mapping‐by‐sequencing, RNA interference and CRISPR/Cas9 techniques, expression analyses, protein–protein interaction assays and Arabidopsis complementation experiments, we examined their potential roles in FM determinacy and carpel formation. We revealed that the incomplete penetrance and variable expressivity of the indeterminate carpel‐inside‐carpel phenotype observed in fruit iterative growth (fig) mutant plants are due to the lack of function of the S. lycopersicum CRC homologue SlCRCa. Furthermore, a detailed functional analysis of tomato CRC paralogues, SlCRCa and SlCRCb, allowed us to propose that they operate as positive regulators of FM determinacy by acting in a compensatory and partially redundant manner to safeguard the proper formation of flowers and fruits. Our results uncover for the first time the physical interaction of putative CRC orthologues with members of the chromatin remodelling complex that epigenetically represses WUSCHEL expression through histone deacetylation to ensure the proper termination of floral stem cell activity.

BELL1 interacts with CRABS CLAW and INNER NO OUTER to regulate ovule and seed development in pomegranate

“…Our results are consistent with those of Phukela et al (2020) . The subcellular localization patterns indicated that the PgCRC protein was located in the nucleus and had typical subcellular localization characteristics of the transcription factor, which was consistent with the results of a previous study reporting SlCRCa, SlCRCb, and PFCRC ( Physalis floridana CRABS CLAW ) localization in the nucleus ( Gong et al, 2021 ; Castañeda et al, 2022 ).…”

“…Tomato CRC paralogues SlCRCa and SlCRCb operate as positive regulators of floral meristem determinacy by acting in a compensatory and partially redundant manner to safeguard the proper formation of flowers and fruits ( Castañeda et al, 2022 ). To explore the putative function of PgCRC in floral organ development, the 35S:: PgCRC construct was introduced into Arabidopsis through Ag.…”

“…CRC is a YABBY transcription factor that acts as a transcriptional activator in nectary development and carpel fusion, and is also involved in floral meristem termination via transcriptional repression ( Gross et al, 2018 ; Castañeda et al, 2022 ). Previous studies have reported that the carpels of crc mutants are broader, shorter, and contain fewer ovules than those of the wild-type (WT), suggesting that CRC is involved in ovule primordia initiation ( Alvarez and Smyth, 1999 ; Bowman and Smyth, 1999 ; Alvarez and Smyth, 2002 ).…”

Candidate Gene Identification and Transcriptome Analysis of Tomato male sterile-30 and Functional Marker Development for ms-30 and Its Alleles, ms-33, 7B-1, and stamenless-2

“…For example, genes associated with tomato tapetum development, such as SlMS10 ( Solyc02g079810 ), Solyc03g113530 (an AtTDF1 homolog), SlAMS ( Solyc08g062780 ), SlMS32 ( Solyc01g081100 ), and SlPHD_MS1 ( Solyc04g008420 ) were downregulated in the stamens of the ms-30 mutant ( Figure 6 C) [ 8 , 9 , 10 , 41 , 42 ]. Conversely, genes related to tomato carpel or ovule development, including SlCRCa ( Solyc01g010240 ), SlCRCb ( Solyc05g012050 ), SlINO ( Solyc05g005240 ), LYRATE ( Solyc05g009380 ), and SlMBP3 ( Solyc06g064840 ), were upregulated in the stamens of the ms-30 mutant ( Figure 6 D) [ 43 , 44 , 45 , 46 ]. These expression differences were validated through qRT-PCR assays ( Figure 6 C,D).…”

“…Examples of such genes are SlMS10 ( Solyc02g079810 ), Solyc03g113530 ( AtTDF1-like1 ), SlAMS ( Solyc08g062780 ), SlMS32 ( Solyc01g081100 ), and SlPHD_MS1 ( Solyc04g008420 ) ( Figure 6 C), which are key components of the DYT1-TDF1-AMS-MS188-MS1 regulatory network [ 8 , 9 , 10 , 41 , 42 ]. Conversely, DEGs that were specifically expressed in wild-type carpels and upregulated in ms-30 stamens included SlCRCa ( Solyc01g010240 ), SlCRCb ( Solyc05g012050 ), SlINO ( Solyc05g005240 ), LYRATE ( Solyc05g009380 ), and SlMBP3 ( Solyc06g064840 ) ( Figure 6 D), suggesting their involvement in carpel or ovule development in tomato [ 43 , 44 , 45 , 46 ]. These findings suggest that TPI positively regulates the genes associated with stamen and pollen development while negatively influencing the genes involved in carpel and ovule development within stamens.…”