Separate elements of theTERMINAL FLOWER 1 cis-regulatory region integrate pathways to control flowering time and shoot meristem identity

Self perpetuation of the shoot meristem is essential for the repetitive initiation of shoot structures during plant development. In Arabidopsis shoot meristem maintenance is disrupted by recessive mutations in the WUSCHEL (WUS) gene. The defect is evident at all developmental stages and is restricted to shoot and floral meristems, whereas the root meristem is not affected. wus mutants fail to properly organize a shoot meristem in the embryo. Postembryonically, defective shoot meristems are initiated repetitively but terminate prematurely in aberrant flat structures. In contrast to wild-type shoot meristems, primordia initiation occurs ectopically across mutant apices, including the center, and often new shoot meristems instead of organs are initiated. The cells of wus shoot apices are larger and more vacuolated than wild-type shoot meristem cells. wus floral meristems terminate prematurely in a central stamen. Double mutant studies indicate that the number of organ primordia in the center of wus flowers is limited, irrespective of organ identity and we propose that meristem cells are allocated into floral whorl domains in a sequential manner. WUS activity also appears to be required for the formation of supernumerary organs in the center of agamous, superman or clavata1 flowers, suggesting that the WUS gene acts upstream of the corresponding genes. Our results suggest that the WUS gene is specifically required for central meristem identity of shoot and floral meristems to maintain their structural and functional integrity.

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FALSIFLORA, the tomato orthologue of FLORICAULA and LEAFY, controls flowering time and floral meristem identity

The Plant Journal ◽

10.1046/j.1365-313x.1999.00641.x ◽

1999 ◽

Vol 20 (6) ◽

pp. 685-693 ◽

Cited By ~ 146

Author(s):

Nuria Molinero-Rosales ◽

Manuel Jamilena ◽

Sergio Zurita ◽

Pedro Gomez ◽

Juan Capel ◽

...

Keyword(s):

Flowering Time ◽

Floral Meristem ◽

Floral Meristem Identity ◽

Meristem Identity

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Flowering time and the identification of floral marker genes in Solanum tuberosum ssp. andigena

Journal of Experimental Botany ◽

10.1093/jxb/erz484 ◽

2019 ◽

Vol 71 (3) ◽

pp. 986-996 ◽

Cited By ~ 1

Author(s):

Tanja Seibert ◽

Christin Abel ◽

Vanessa Wahl

Keyword(s):

Flowering Time ◽

Developmental Stages ◽

Expression Patterns ◽

Marker Genes ◽

Flower Meristem ◽

Growth Regime ◽

Long Day ◽

Storage Organs ◽

Meristem Identity ◽

Meristem Identity Gene

Abstract Solanaceae is a family of flowering plants that includes agricultural species such as tomato (Solanum lycopersicum), eggplant (S. melongena), pepper (Capsicum annuum), and potato (S. tuberosum). The transition from the vegetative to reproductive stage has been extensively investigated in tomato as it affects fruit yield. While potato has mainly been studied with regards to the formation of storage organs, control of flowering time is a subject of increasing interest as development of true seeds is becoming more important for future breeding strategies. Here, we describe a robust growth regime for synchronized development of S. tuberosum ssp. andigena. Using SEM to analyse the developmental stages of the shoot apical meristem (SAM) throughout the floral transition, we show that andigena is a facultative long-day plant with respect to flowering. In addition, we identify the flower meristem identity gene MACROCALYX (StMC) as a marker to distinguish between the vegetative and reproductive stages. We show that the expression of WUSCHEL HOMEOBOX 9 (StWOX9) and ANANTHA (StAN) are specific to the inflorescence meristem and flower meristems in the cyme, respectively. The expression patterns of homologs of Arabidopsis flowering-time regulators were studied, and indicated that SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (StSOC1) and StFD might regulate flowering similar to other plant species.

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