scholarly journals Nature of Floral Stimulus in Perilla as Studied by Grafting. II. Role of endogenous gibberellins and retention of floral stimulus in floral organ.

1992 ◽  
Vol 61 (1) ◽  
pp. 107-111 ◽  
Author(s):  
Hiroshi SUGE
Keyword(s):  
Development ◽  
1999 ◽  
Vol 126 (3) ◽  
pp. 469-481 ◽  
Author(s):  
K. Lynn ◽  
A. Fernandez ◽  
M. Aida ◽  
J. Sedbrook ◽  
M. Tasaka ◽  
...  

Several lines of evidence indicate that the adaxial leaf domain possesses a unique competence to form shoot apical meristems. Factors required for this competence are expected to cause a defect in shoot apical meristem formation when inactivated and to be expressed or active preferentially in the adaxial leaf domain. PINHEAD, a member of a family of proteins that includes the translation factor eIF2C, is required for reliable formation of primary and axillary shoot apical meristems. In addition to high-level expression in the vasculature, we find that low-level PINHEAD expression defines a novel domain of positional identity in the plant. This domain consists of adaxial leaf primordia and the meristem. These findings suggest that the PINHEAD gene product may be a component of a hypothetical meristem forming competence factor. We also describe defects in floral organ number and shape, as well as aberrant embryo and ovule development associated with pinhead mutants, thus elaborating on the role of PINHEAD in Arabidopsis development. In addition, we find that embryos doubly mutant for PINHEAD and ARGONAUTE1, a related, ubiquitously expressed family member, fail to progress to bilateral symmetry and do not accumulate the SHOOT MERISTEMLESS protein. Therefore PINHEAD and ARGONAUTE1 together act to allow wild-type growth and gene expression patterns during embryogenesis.


2020 ◽  
Author(s):  
Chunling Zhang ◽  
Yalin Sun ◽  
Ludan Wei ◽  
Wenjing Wang ◽  
Hang Li ◽  
...  

Abstract Background: Members of AP1/FUL subfamily genes play an essential role in the regulation of floral meristem transition, floral organ identity, and fruit ripping. At present, there have been insufficient studies to explain the function of the AP1/FUL-like subfamily genes in Asteraceae. Results: Here, we cloned two euAP1 clade genes TeAP1-1 and TeAP1-2, and three euFUL clade genes TeFUL1, TeFUL2, and TeFUL3 from marigold (Tagetes erecta). Expression profile analysis demonstrated that TeAP1-1 and TeAP1-2 were mainly expressed in receptacles, sepals, petals, and ovules. TeFUL1 and TeFUL3 were expressed in floral buds, stems and leaves as well as in productive tissues, while TeFUL2 was mainly expressed in floral buds and vegetative tissues. Transgenic Arabidopsis lines showed that overexpression TeAP1-2 or TeFUL2 resulted in early flowering, implying that these two genes might regulate the floral transition. Yeast two-hybrid analysis indicated that TeAP1/FUL proteins only interacted with TeSEP proteins to form heterodimers, and that TeFUL2 could also form a homodimer.Conclusion: In general, TeAP1-1 and TeAP1-2 might play a conserved role in regulating sepal and petal identity, just like the role of MADS-box class A genes, while TeFUL genes might display divergent functions. This study provides an insight into molecular mechanism of AP1/FUL-like genes in Asteraceae species.


2020 ◽  
Author(s):  
Tong Zhao ◽  
Alma Piñeyro-Nelson ◽  
Qianxia Yu ◽  
Xiaoying Hu ◽  
Huanfang Liu ◽  
...  

Abstract Background:The flower of Hedychium coronarium possesses highly specialized floral organs: a synsepalous calyx, petaloid staminodes and a labellum. The formation of these organs is controlled by two gene categories: floral organ identity genes and organ boundary genes, which may function individually or jointly during flower development. Although the floral organogenesis of H. coronarium has been studied at the morphological level, the underlying molecular mechanisms involved in its floral development still remain poorly understood. In addition, previous works analyzing the role of MADS-box genes in controlling floral organ specification in some Zingiberaceae did not address the molecular mechanisms involved in the formation of particular organ morphologies that emerge later in flower development, such as the synsepalous calyx formed through intercalary growth of adjacent sepals. Results:Here, we used comparative transcriptomics combined with Real-time quantitative PCR and mRNA in situ hybridization to investigate gene expression patterns of ABC-class genes in H. coronarium flowers, as well as the homolog of the organ boundary gene PETAL LOSS (HcPTL). qRT-PCR detection showed that HcAP3 and HcAG were expressed in both the petaloid staminode and the fertile stamen. mRNA in situ hybridization showed that HcPTL was expressed in developing meristems, including cincinnus primordia, floral primordia, common primordia and almost all new initiating floral organ primordia.Conclusions:Our studies found that stamen/petal identity or stamen fertility in H. coronarium was not necessarily correlated with the differential expression of HcAP3 and HcAG. We also found a novel spatio-temporal expression pattern for HcPTL mRNA, suggesting it may have evolved a lineage-specific role in the morphogenesis of the Hedychium flower. Our study provides a new transcriptome reference and a functional hypothesis regarding the role of a boundary gene in organ fusion that should be further addressed through phylogenetic analyzes of this gene, as well as functional studies.


2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Lulu Wang ◽  
Yi Li ◽  
Xingyue Jin ◽  
Liping Liu ◽  
Xiaozhuan Dai ◽  
...  

AbstractProper flower development is essential for sexual reproductive success and the setting of fruits and seeds. The availability of a high quality genome sequence for pineapple makes it an excellent model for studying fruit and floral organ development. In this study, we sequenced 27 different pineapple floral samples and integrated nine published RNA-seq datasets to generate tissue- and stage-specific transcriptomic profiles. Pairwise comparisons and weighted gene co-expression network analysis successfully identified ovule-, stamen-, petal- and fruit-specific modules as well as hub genes involved in ovule, fruit and petal development. In situ hybridization confirmed the enriched expression of six genes in developing ovules and stamens. Mutant characterization and complementation analysis revealed the important role of the subtilase gene AcSBT1.8 in petal development. This work provides an important genomic resource for functional analysis of pineapple floral organ growth and fruit development and sheds light on molecular networks underlying pineapple reproductive organ growth.


1969 ◽  
Vol 58 (4) ◽  
pp. 393-405
Author(s):  
Teh-ling Chu ◽  
J. L. Serapión

The role played by leaves in the perception and inhibition of the flowering stimulus was studied through defoliation treatment in three sugarcane varieties. It was found that the expanding leaves (0 and —1) in the variety P.R. 980 appear to be most effective in producing a flowering stimulus. The mature leaves (+3 and +4) in the variety Cl 41-223 appear to produce a transmissible flowering inhibitor. Absence of the young leaves within the leaf spindle during a period critical to initiation of inflorescence primordia resulted in a significant reduction of flowering intensity in varieties N.Co. 310 and Cl 41-223, and a marked delay in the flowering time in N.Co. 310. Removal of these leaves during subsequent stages of inflorescence caused a somewhat depressive flowering response and a considerable delay in the flowering time of N.Co. 310. A late-initiating variety, Cl 41-223 appears to begin producing a floral stimulus around August 20, about 2 to 3 weeks later than that of the early-initiating variety N.Co. 310.


Development ◽  
2004 ◽  
Vol 131 (19) ◽  
pp. 4697-4707 ◽  
Author(s):  
J. Pfluger
Keyword(s):  

1971 ◽  
Vol 49 (6) ◽  
pp. 803-819 ◽  
Author(s):  
Georges Bernier

This paper is a review dealing with the various structural and metabolic changes that have been described in the shoot apex in transition to flowering. Evaluation of the significance of these changes can tentatively be made only in cases where a, the timing of physiological events in the plant, particularly the time of movement of the floral stimulus, is reasonably well known; b, the timing and localization of events in the shoot apex are known.For each of the best known cases (Xanthium, Pharbitis, Sinapis, Lolium, Chenopodium), the temporal sequence of events in the target cells of the apical meristem is described and the sequences are compared. Three successive phases of general occurrence are distinguished.1. The evocation phase, including the events occurring at the presumed time of arrival of the floral stimulus at the meristem. During this phase, RNA and protein molecules essential to the flowering process are synthesized.2. The mitotic phase, characterized by the release in mitosis of cells that are in the postsynthetic G2 phase of the mitotic cycle.3. The morphogenesis phase, including the events leading to the production of flower buds.The essentiality and role of the phases are discussed in relation with current views on cell differentiation.


HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 973A-973
Author(s):  
Denise Duclos ◽  
Thomas Björkman

The genetic factors that control reproductive development in B. oleracea remain a mystery. Broccoli differs from cauliflower in its floral development stage at harvest. We are studying the role of meristem identity genes (MIGs) in the transition from inflorescence meristem (cauliflower) to floral buds (broccoli). The objectives are to determine stage-specific roles of MIGs during reproductive development and to check whether expression of flowering genes in heading B. oleracea is as predicted by the Arabidopsis flowering model. We tested a model of arrest in B. oleracea that incorporates FUL, a redundant gene of AP1 in controlling inflorescence architecture and floral meristem identity, the meristem gene TFL1, the flowering gene LFY, and AP1/CAL, and genes involved in flower transition. Conclusions. 1) Arrest at the inflorescence meristem stage is highly correlated with a decrease in LFY to TFL1 ratio, given by a decrease in TFL1 expression. 2) Transcription of AP1c is stimulated at the time of floral primordium initiation, suggesting a role in floral transition but not in floral organ specification. Plants recessive for AP1a, AP1c, and CAL formed normal floral buds containing all four whorls of organs, and did not necessarily form curd. We suggest that their ability to flower could be related with the ectopic expression of FUL by affecting TFL1 expression. FUL paralogs were highly expressed at all stages of development of the triple mutant plants. 3) The lack of upregulation in AP1 transcripts at the floral bud stage, and the absence of an A-function mutant phenotype imply that other genes act redundantly with AP1 in the specification of sepal identity and questions the role of AP1a and AP1c as A-function genes in B. oleracea.


2013 ◽  
Vol 64 (2) ◽  
Author(s):  
Zaidah Rahmat ◽  
Ma Nyuk Ling ◽  
Harikrishan Kulaveerasingam ◽  
Sharifah Shahrul Rabiah Syed Alwee ◽  
Meilina Ong Abdullah

The oil palm industry has been affected by abnormality in its clonal palm. Oil palm abnormality which arose from in vitro regeneration was first detected during flowering process. In this study, localized expression of an oil palm homologue of SOC1 gene was investigated using in situ RNA hybridization. Tissue specific localization expression of OPSOC1and OPSOC1-3’ showed that SOC1 is expressed in both normal and abnormal flower. The gene is highly expressed in abnormal oil palm flower throughout flower initiation and development. The role of SOC1 in inducing floral organ and its expression pattern provides a better understanding of regulation of OPSOC1 in normal and abnormal oil palm flower.


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