Brassinosteroid Regulates Root Development with Highly Redundant Genes in Hexaploid Wheat

2019 ◽  
Vol 60 (8) ◽  
pp. 1761-1777 ◽  
Author(s):  
Lijiang Hou ◽  
Aihua Zhang ◽  
Ruochen Wang ◽  
Peng Zhao ◽  
Dongzhi Zhang ◽  
...  
Keyword(s):  
Root Development ◽  
Hexaploid Wheat ◽  
Glycogen Synthase ◽  
Abiotic Stress Tolerance ◽  
Point Mutations ◽  
Triticum Aestivum L ◽  
Wheat Root ◽  
Homologous Gene ◽  
Evolutionary Divergence ◽  
Biotic And Abiotic Stress

Abstract Brassinosteroid (BR) plays an important role in plant development and biotic and abiotic stress tolerance, but its specific function remains largely unknown in wheat (Triticum aestivum L.), preventing its utilization in this important crop. In this study, the function of BR and its underlying cytological role in wheat root development were comprehensively investigated. Our findings demonstrated that BR has a conserved function in regulating root length in wheat, and novel roles in regulating lateral root emergence and root diameter were uncovered. Analyses of BR homologous gene composition and evolutionary divergence demonstrated that the genetic framework of the wheat BR pathway was close to that of rice, but contained highly redundant homologous copies of genes from the subgenome A, B and D. These homologous copies showed active expression and shared a conserved BR response. The expression of wheat DWF4 and glycogen synthase kinase (GSK) genes in Arabidopsis confirmed that multiple homologous copies maintained their conserved function in regulating root development, highlighting their redundant status and indicating that a special challenge exists in wheat gene modification to deal with this high redundancy. However, our results suggested that the hypermorphic effect of T. aestivum GSK (TaGSK) genes with point mutations may be an effective approach to overcome this redundancy in the manipulation of BR signaling in wheat. Our study provides fundamental data uncovering the function of BR in wheat root development, the underlying genetic basis and a possible strategy to manipulate BR signaling in hexaploid wheat.

Characterization of elite bread wheat (Triticum aestivum L.) germplasm for spot blotch Bipolaris sorokiniana (Sacc.) Shoemaker resistance

2021 ◽  
pp. 1-8
Author(s):  
Deep Shikha ◽  
Chandani Latwal ◽  
Elangbam Premabati Devi ◽  
Anupama Singh ◽  
Pawan K. Singh ◽  
...  
Keyword(s):  
Abiotic Stress Tolerance ◽  
Bipolaris Sorokiniana ◽  
Triticum Aestivum L ◽  
Spot Blotch ◽  
Biotic And Abiotic Stress ◽  
Wheat Varieties ◽  
Effective Measure ◽  
Breeding Lines ◽  
Elite Breeding Lines ◽  
Germplasm Accessions

Abstract Genetic resources are of paramount importance for developing improved crop varieties, particularly for biotic and abiotic stress tolerance. Spot blotch (SB) is a destructive foliar disease of wheat prevalent in warm and humid regions of the world, especially in the eastern parts of South Asia. For the management of this disease, the most effective measure is the development of resistant cultivars. Thus, the present investigation was carried out to confirm SB resistance in 200 germplasm accessions based on phenotypic observations and molecular characterization. These elite breeding lines obtained from the International Centre for Maize and Wheat Improvement, Mexico, are developed deploying multiple parentages. These lines were screened for SB resistance in the field under artificially created epiphytotic conditions during 2014–15 and 2015–16 along with two susceptible checks (CIANO T79 and Sonalika) and two resistant checks (Chirya 3 and Francolin). Eighty-two out of 200 germplasm accessions were found resistant to SB and resistance in these lines was confirmed with a specific SSR marker Xgwm148. Three accessions, VORONA/CNO79, KAUZ*3//DOVE/BUC and JUP/BJY//URES/3/HD2206/HORK//BUC/BUL were observed possessing better resistance than the well-known SB-resistant genotype Chirya3. These newly identified resistant lines could be used by wheat breeders for developing SB-resistant wheat varieties.

scholarly journals Evolutionary Divergence and Biased Expression of NAC Transcription Factors in Hexaploid Bread Wheat (Triticum aestivum L.)

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 382
Author(s):  
Jianhui Ma ◽  
Meng Yuan ◽  
Bo Sun ◽  
Daijing Zhang ◽  
Jie Zhang ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Transcription Factors ◽  
Abiotic Stress ◽  
Hexaploid Wheat ◽  
Evolutionary Divergence ◽  
Snp Analysis ◽  
Biotic And Abiotic Stress ◽  
Nac Transcription Factors ◽  
Group I ◽  
Wide Range

The NAC genes, a large plant-specific family of transcription factors, regulate a wide range of pathways involved in development and response to biotic and abiotic stress. In this study, the NAC transcription factors were identified in 27 green plants, and the results showed that NAC transcription factors in plants undergo an appearance stage from water to land and a number expansion stage from gymnosperm to angiosperm. Investigating the evolutionary process of the NAC transcription factors from diploid species to hexaploid wheat revealed that tandem replications during the polyploidization process is an important event for increasing the number of NAC transcription factors in wheat. Then, the molecular characteristics, phylogenetic relationships, and expression patterns of 462 NAC transcription factors of hexaploid wheat (TaNACs) were analyzed. The protein structure results showed that TaNAC was relatively conservative at the N-terminal that contains five subdomains. All these TaNACs were divided into Group I and Group II by phylogenetic analysis, and the TaNACs in Group I should undergo strong artificial selection based on single nucleotide polymorphism (SNP) analysis. Through genome synteny and phylogenetic analysis, these TaNACs were classified into 88 groups and 9 clusters. The biased expression results of these TaNACs showed that there are 24 groups and 67 groups of neofunctionalization genes under biotic and abiotic stress, respectively, and 16 groups and 59 groups of subfunctionalization genes. This shows that neofunctionalization plays an important role in coping with different stresses. Our study provides new insights into the evolution of NAC transcription factors in hexaploid wheat.

scholarly journals Histone acetyltransferase TaHAG1 acts as a crucial regulator to strengthen salt tolerance of hexaploid wheat

2021 ◽  
Author(s):  
Mei Zheng ◽  
Jingchen Lin ◽  
Xingbei Liu ◽  
Wei Chu ◽  
Jinpeng Li ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Bread Wheat ◽  
Hexaploid Wheat ◽  
Histone Acetyltransferase ◽  
Tetraploid Wheat ◽  
Triticum Aestivum L ◽  
Ros Production ◽  
Signal Specificity ◽  
H3 Acetylation

Abstract Polyploidy occurs prevalently and plays an important role during plant speciation and evolution. This phenomenon suggests polyploidy could develop novel features that enable them to adapt wider range of environmental conditions compared with diploid progenitors. Bread wheat (Triticum aestivum L., BBAADD) is a typical allohexaploid species and generally exhibits greater salt tolerance than its tetraploid wheat progenitor (BBAA). However, little is known about the underlying molecular basis and the regulatory pathway of this trait. Here, we show that the histone acetyltransferase TaHAG1 acts as a crucial regulator to strengthen salt tolerance of hexaploid wheat. Salinity-induced TaHAG1 expression was associated with tolerance variation in polyploidy wheat. Overexpression, silencing and CRISPR-mediated knockout of TaHAG1 validated the role of TaHAG1 in salinity tolerance of wheat. TaHAG1 contributed to salt tolerance by modulating ROS production and signal specificity. Moreover, TaHAG1 directly targeted a subset of genes that are responsible for hydrogen peroxide production, and enrichment of TaHAG1 triggered increased H3 acetylation and transcriptional upregulation of these loci under salt stress. In addition, we found the salinity-induced TaHAG1-mediated ROS production pathway is involved in salt tolerance difference of wheat accessions with varying ploidy. Our findings provide insight into the molecular mechanism of how an epigenetic regulatory factor facilitates adaptability of polyploidy wheat and highlights this epigenetic modulator as a strategy for salt tolerance breeding in bread wheat.

Phylogenetic relationships of five morphological groups of hexaploid wheat (Triticum aestivum L. em Thell.) based on RAPD analysis

Genome ◽  
2000 ◽  
Vol 43 (4) ◽  
pp. 724-727 ◽  
Author(s):  
Wenguang Cao ◽  
G Scoles ◽  
P Hucl ◽  
R N Chibbar
Keyword(s):  
Hexaploid Wheat ◽  
Phylogenetic Relationships ◽  
Genetic Similarity ◽  
Rapd Analysis ◽  
Genetic Relationships ◽  
Random Amplified Polymorphic Dna ◽  
Triticum Aestivum L ◽  
Similarity Coefficients ◽  
Morphological Classification ◽  
Wild Wheat

The genetic relationships among the five groups of hexaploid wheat: common, spelta, macha, vavilovii, and semi-wild wheat (SWW) are not clear. Random amplified polymorphic DNA (RAPD) analysis was used to assess phylogenetic relationships among these five morphological groups of hexaploid wheat. RAPD data were analyzed using the NTSYS-PC computer program to generate Jaccard genetic similarity coefficients. A dendrogram based on RAPD analysis grouped 15 accessions into five distinct clusters. These results are in agreement with those based on morphological classification, suggesting that common wheat is most closely related to SWW, followed by spelta, vavilovii, and macha.Key words: RAPD, macha, spelta, vavilovii, semi-wild wheat, phylogenetic relationships.

Cytogenetic analyses of intergeneric hybrids between barley and nine species of Elymus

Genome ◽  
2008 ◽  
Vol 51 (11) ◽  
pp. 897-904 ◽  
Author(s):  
N.-S. Kim ◽  
G. Fedak ◽  
F. Han ◽  
W. Cao
Keyword(s):  
Wild Species ◽  
Meiotic Chromosome ◽  
Abiotic Stress Tolerance ◽  
Chromosome Analysis ◽  
Intergeneric Hybrids ◽  
Biotic And Abiotic Stress ◽  
Crop Species ◽  
Barley Cultivars ◽  
Bivalent Formation ◽  
Gish Analysis

Wild species in the Triticeae tribe are very valuable resources for agronomic improvement in cereal crop species. Intergeneric hybrids were produced between several barley cultivars and perennial species in the genera Elymus , Thinopyrum , and Pseudoroegneria . Caryopsis formation and subsequent plantlet regeneration from embryo culture were variable depending on the hybrid combinations. Chromosome numbers and hybrid identity were confirmed by GISH analysis on the somatic cells of the hybrids. While the hybrids showed very robust vegetative growth and exceeded the parental spikes in size, their floral morphologies resembled that of the wild species. Meiotic chromosome analysis revealed that the bivalent formation frequency per cell ranged from 0.06 in Hordeum vulgare ‘Betzes’ × Elymus curvatus to 3.0 in Elymus humidus  × H. vulgare ‘Manley’. By GISH analysis on the meiocytes of the hybrid E. humidus × ‘Manley’, the frequency of autosyndetic bivalents exceeded the allosyndetic bivalent formation, which gave an insight into the genome constitution of E. humidus as an autoallohexploid species. Regardless of the low allosyndetic chromosome pairing between barley and E. humidus, this combination may be useful for further input, since E. humidus is known to carry many valuable genes for biotic and abiotic stress tolerance.

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