scholarly journals The SINGLE FLOWER (SFL) gene encodes a MYB transcription factor that regulates the number of flowers produced by the inflorescence of chickpea

2020 ◽  
Author(s):  
Cristina Caballo ◽  
Ana Berbel ◽  
Raul Ortega ◽  
Juan Gil ◽  
Teresa Millán ◽  
...  

SUMMARYresearch conducted & rationaleLegume species usually have compound inflorescences, where flowers appear in secondary inflorescences (I2), at lateral positions of the primary inflorescence (I1), in contrast to simple inflorescences, as in Arabidopsis, where flowers are formed in the primary inflorescence stem. The number of flowers per I2, characteristic of each legume species, determines inflorescence diversity, and the number of pods produced, which can affect yield. Gene Regulatory Network that controls the activity of I2 meristems, and therefore the number of flowers per secondary inflorescence is mostly unknown, as well as how specific are factors controlling this trait and whether they share this function in other meristems.methodsChickpea produces one flower per I2 but single flower (sfl) mutants produce two (double-pod phenotype). By mapping the sfl-d mutation and identification and analysis of a second mutant allele we have isolated SFL. We used scanning electron microscopy to study the effect of sfl mutations on inflorescence ontogeny and in situ hybridization to study the expression of SFL and of meristem identity genes in the developing chickpea inflorescence.key resultWe show that the SFL gene corresponds to CaRAX1/2a, encoding a MYB transcription factor. Our results show that CaRAX1/2a / SFL is specifically expressed in the I2 meristem, possibly activated by CaVEGETATIVE1.main conclusion & key points for discussionOur findings reveal that SFL plays a central role in the control of chickpea inflorescence architecture, specifically acting in the I2 meristem to control the time length for which it is active, and therefore determining the number of floral meristems that it can produce.

Development ◽  
1998 ◽  
Vol 125 (4) ◽  
pp. 733-742 ◽  
Author(s):  
E. Souer ◽  
A. van der Krol ◽  
D. Kloos ◽  
C. Spelt ◽  
M. Bliek ◽  
...  

A main determinant of inflorescence architecture is the site where floral meristems are initiated. We show that in wild-type Petunia bifurcation of the inflorescence meristem yields two meristems of approximately equal size. One terminates into a floral meristem and the other maintains its inflorescence identity. By random transposon mutagenesis we have generated two mutants in which the architecture of the inflorescence is altered. In the extra petals- (exp) mutant the inflorescence terminates with the formation of a single terminal flower. Phenotypic analysis showed that exp is required for the bifurcation of inflorescence meristems. In contrast, the aberrant leaf and flower- (alf) mutant is affected in the specification of floral meristem identity while the branching pattern of the inflorescence remains unaltered. A weak alf allele was identified that, after bifurcation of the inflorescence meristem, yields a ‘floral’ meristem with partial inflorescence characteristics. By analysing independent transposon dTph1 insertion alleles we show that the alf locus encodes the Petunia FLORICAULA/LEAFY homolog. In situ hybridisation shows that alf is expressed in the floral meristem and also in the vegetative meristem. Differences and similarities between these Petunia mutants and mutations affecting inflorescence architecture in other species will be discussed.


2020 ◽  
Vol 71 (22) ◽  
pp. 7118-7131
Author(s):  
Yi Shang ◽  
Lu Yuan ◽  
Zhaocan Di ◽  
Yong Jia ◽  
Zhenlan Zhang ◽  
...  

Abstract Barley possesses a branchless, spike-shaped inflorescence where determinate spikelets attach directly to the main axis, but the developmental mechanism of spikelet identity remains largely unknown. Here we report the functional analysis of the barley gene BRANCHED AND INDETERMINATE SPIKELET 1 (BDI1), which encodes a TCP transcription factor and plays a crucial role in determining barley inflorescence architecture and spikelet development. The bdi1 mutant exhibited indeterminate spikelet meristems that continued to grow and differentiate after producing a floret meristem; some spikelet meristems at the base of the spike formed two fully developed seeds or converted to branched spikelets, producing a branched inflorescence. Map-based cloning analysis showed that this mutant has a deletion of ~600 kb on chromosome 5H containing three putative genes. Expression analysis and virus-induced gene silencing confirmed that the causative gene, BDI1, encodes a CYC/TB1-type TCP transcription factor and is highly conserved in both wild and cultivated barley. Transcriptome and regulatory network analysis demonstrated that BDI1 may integrate regulation of gene transcription cell wall modification and known trehalose-6-phosphate homeostasis to control spikelet development. Together, our findings reveal that BDI1 represents a key regulator of inflorescence architecture and meristem determinacy in cereal crop plants.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Fangwei Yu ◽  
Shenyun Wang ◽  
Wei Zhang ◽  
Hong Wang ◽  
Li Yu ◽  
...  

Abstract The members of myeloblastosis transcription factor (MYB TF) family are involved in the regulation of biotic and abiotic stresses in plants. However, the role of MYB TF in phosphorus remobilization remains largely unexplored. In the present study, we show that an R2R3 type MYB transcription factor, MYB103, is involved in phosphorus (P) remobilization. MYB103 was remarkably induced by P deficiency in cabbage (Brassica oleracea var. capitata L.). As cabbage lacks the proper mutant for elucidating the mechanism of MYB103 in P deficiency, another member of the crucifer family, Arabidopsis thaliana was chosen for further study. The transcript of its homologue AtMYB103 was also elevated in response to P deficiency in A. thaliana, while disruption of AtMYB103 (myb103) exhibited increased sensitivity to P deficiency, accompanied with decreased tissue biomass and soluble P concentration. Furthermore, AtMYB103 was involved in the P reutilization from cell wall, as less P was released from the cell wall in myb103 than in wildtype, coinciding with the reduction of ethylene production. Taken together, our results uncover an important role of MYB103 in the P remobilization, presumably through ethylene signaling.


Author(s):  
Junping Yu ◽  
Guolong Zhao ◽  
Wei Li ◽  
Ying Zhang ◽  
Peng Wang ◽  
...  

Abstract Key message Identification and functional analysis of the male sterile gene MS6 in Glycine max. Abstract Soybean (Glycine max (L.) Merr.) is an important crop providing vegetable oil and protein. The male sterility-based hybrid breeding is a promising method for improving soybean yield to meet the globally growing demand. In this research, we identified a soybean genic male sterile locus, MS6, by combining the bulked segregant analysis sequencing method and the map-based cloning technology. MS6, highly expressed in anther, encodes an R2R3 MYB transcription factor (GmTDF1-1) that is homologous to Tapetal Development and Function 1, a key factor for anther development in Arabidopsis and rice. In male sterile ms6 (Ames1), the mutant allele contains a missense mutation, leading to the 76th leucine substituted by histidine in the DNA binding domain of GmTDF1-1. The expression of soybean MS6 under the control of the AtTDF1 promoter could rescue the male sterility of attdf1 but ms6 could not. Additionally, ms6 overexpression in wild-type Arabidopsis did not affect anther development. These results evidence that GmTDF1-1 is a functional TDF1 homolog and L76H disrupts its function. Notably, GmTDF1-1 shows 92% sequence identity with another soybean protein termed as GmTDF1-2, whose active expression also restored the fertility of attdf1. However, GmTDF1-2 is constitutively expressed at a very low level in soybean, and therefore, not able to compensate for the MS6 deficiency. Analysis of the TDF1-involved anther development regulatory pathway showed that expressions of the genes downstream of TDF1 are significantly suppressed in ms6, unveiling that GmTDF1-1 is a core transcription factor regulating soybean anther development.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Arun Kumaran Anguraj Vadivel ◽  
Tim McDowell ◽  
Justin B. Renaud ◽  
Sangeeta Dhaubhadel

AbstractGmMYB176 is an R1 MYB transcription factor that regulates multiple genes in the isoflavonoid biosynthetic pathway, thereby affecting their levels in soybean roots. While GmMYB176 is important for isoflavonoid synthesis, it is not sufficient for the function and requires additional cofactor(s). The aim of this study was to identify the GmMYB176 interactome for the regulation of isoflavonoid biosynthesis in soybean. Here, we demonstrate that a bZIP transcription factor GmbZIP5 co-immunoprecipitates with GmMYB176 and shows protein–protein interaction in planta. RNAi silencing of GmbZIP5 reduced the isoflavonoid level in soybean hairy roots. Furthermore, co-overexpression of GmMYB176 and GmbZIP5 enhanced the level of multiple isoflavonoid phytoallexins including glyceollin, isowighteone and a unique O-methylhydroxy isoflavone in soybean hairy roots. These findings could be utilized to develop biotechnological strategies to manipulate the metabolite levels either to enhance plant defense mechanisms or for human health benefits in soybean or other economically important crops.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kaijie Zheng ◽  
Xutong Wang ◽  
Yating Wang ◽  
Shucai Wang

Abstract Background Trichome initiation in Arabidopsis is regulated by a MYB-bHLH-WD40 (MBW) transcriptional activator complex formed by the R2R3 MYB transcription factor GLABRA1 (GL1), MYB23 or MYB82, the bHLH transcription factor GLABRA3 (GL3), ENHANCER OF GLABRA3 (EGL3) or TRANSPARENT TESTA8 (TT8), and the WD40-repeat protein TRANSPARENT TESTA GLABRA1 (TTG1). However, the functions of the rice homologs of the MBW complex proteins remained uncharacterized. Results Based on amino acid sequence identity and similarity, and protein interaction prediction, we identified OsGL1s, OsGL3s and OsTTG1s as rice homologs of the MBW complex proteins. By using protoplast transfection, we show that OsGL1D, OsGL1E, OsGL3B and OsTTG1A were predominantly localized in the nucleus, OsGL3B functions as a transcriptional activator and is able to interact with GL1 and TTG1. By using yeast two-hybrid and protoplast transfection assays, we show that OsGL3B is able to interact with OsGL1E and OsTTG1A, and OsGL1E and OsTTG1A are also able to interact with GL3. On the other hand, we found that OsGL1D functions as a transcription activator, and it can interact with GL3 but not OsGL3B. Furthermore, our results show that expression of OsTTG1A in the ttg1 mutant restored the phenotypes including alternations in trichome and root hair formation, seed color, mucilage production and anthocyanin biosynthesis, indicating that OsTTG1A and TTG1 may have similar functions. Conclusion These results suggest that the rice homologs of the Arabidopsis MBW complex proteins are able to form MBW complexes, but may have conserved and non-conserved functions.


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