Regulatory network of NAC transcription factors in leaf senescence

Abstract Background Leaf senescence delay impacts positively in grain yield by maintaining the photosynthetic area during the reproductive stage and during grain filling. Therefore a comprehensive understanding of the gene families associated with leaf senescence is essential. NAC transcription factors (TF) form a large plant-specific gene family involved in regulating development, senescence, and responses to biotic and abiotic stresses. The main goal of this work was to identify sunflower NAC TF (HaNAC) and their association with senescence, studying their orthologous to understand possible functional relationships between genes of different species. Results To clarify the orthologous relationships, we used an in-depth comparative study of four divergent taxa, in dicots and monocots, with completely sequenced genomes (Arabidopsis thaliana, Vitis vinifera, Musa acuminata and Oryza sativa). These orthologous groups provide a curated resource for large scale protein sequence annotation of NAC TF. From the 151 HaNAC genes detected in the latest version of the sunflower genome, 50 genes were associated with senescence traits. These genes showed significant differential expression in two contrasting lines according to an RNAseq assay. An assessment of overexpressing the Arabidopsis line for HaNAC001 (a gene of the same orthologous group of Arabidopsis thaliana ORE1) revealed that this line displayed a significantly higher number of senescent leaves and a pronounced change in development rate. Conclusions This finding suggests HaNAC001 as an interesting candidate to explore the molecular regulation of senescence in sunflower.

Download Full-text

Conserved residues in the wheat (Triticum aestivum) NAM-A1 NAC domain are required for protein binding and when mutated lead to delayed peduncle and flag leaf senescence

10.1101/573881 ◽

2019 ◽

Cited By ~ 3

Author(s):

Sophie A. Harrington ◽

Lauren E. Overend ◽

Nicolas Cobo ◽

Philippa Borrill ◽

Cristobal Uauy

Keyword(s):

Transcription Factors ◽

Leaf Senescence ◽

Protein Function ◽

Flag Leaf ◽

Missense Mutations ◽

In Planta ◽

Conserved Residues ◽

Nac Domain ◽

Nac Transcription Factors ◽

The Impact

AbstractBackgroundNAC transcription factors contain five highly conserved subdomains which are required for protein dimerisation and DNA binding. Few residues within these subdomains have been identified as essential for protein function, and fewer still have been shown to be of biological relevancein planta. Here we use a positive regulator of senescence in wheat,NAM-A1, to test the impact of missense mutations at specific, highly conserved residues of the NAC domain on protein function.ResultsWe identified missense mutations in five highly conserved residues of the NAC domain ofNAM-A1in a tetraploid TILLING population. TILLING lines containing these mutations, alongside synonymous and non-conserved mutation controls, were grown under glasshouse conditions and scored for senescence. Four of the five mutations showed a significant and consistent delay in peduncle senescence but had no consistent effects on flag leaf senescence. All four mutant alleles with the delayed senescence phenotype also lost the ability to interact with the homoeolog NAM-B1 in a yeast two-hybrid assay. Two of these residues were previously shown to be involved in NAC domain function in Arabidopsis, suggesting conservation of residue function between species. Three of these four alleles led to an attenuated cell death response compared to wild-typeNAM-A1when transiently over-expressed inNicotiana benthamiana. One of these mutations was further tested under field conditions, in which there was a significant and consistent delay in both peduncle and leaf senescence.ConclusionsWe combined field and glasshouse studies of a series of mutant alleles with biochemical analyses to identify four residues of the NAC domain which are required forNAM-A1function and protein interaction. We show that mutations in these residues lead to a gradient of phenotypes, raising the possibility of developing allelic series of mutations for traits of agronomic importance. We also show that mutations inNAM-A1more severely impact peduncle senescence, compared to the more commonly studied flag leaf senescence, highlighting this as an area deserving of further study. The results from this integrated approach provide strong evidence that conserved residues within the functional domains of NAC transcription factors have biological significancein planta.

Download Full-text

kNACking on heaven’s door: how important are NAC transcription factors for leaf senescence and Fe/Zn remobilization to seeds?

Frontiers in Plant Science ◽

10.3389/fpls.2013.00226 ◽

2013 ◽

Vol 4 ◽

Cited By ~ 22

Author(s):

Felipe Klein Ricachenevsky ◽

Paloma Koprovski Menguer ◽

Raul Antonio Sperotto

Keyword(s):

Transcription Factors ◽

Leaf Senescence ◽

Nac Transcription Factors

Download Full-text

Gene Expression Correlation Analysis Reveals MYC-NAC Regulatory Network in Cotton Pigment Gland Development

International Journal of Molecular Sciences ◽

10.3390/ijms22095007 ◽

2021 ◽

Vol 22 (9) ◽

pp. 5007

Author(s):

Hailiang Cheng ◽

Xiaoxu Feng ◽

Dongyun Zuo ◽

Youping Zhang ◽

Qiaolian Wang ◽

...

Keyword(s):

Transcription Factors ◽

Correlation Analysis ◽

Regulatory Network ◽

Pigment Gland ◽

Interaction Network ◽

Nac Transcription Factors ◽

Expression Correlation ◽

Dna Binding Sites ◽

Gene Expression Correlation ◽

Gland Development

Plant NAC (NAM, ATAF1/2, and CUC2) family is involved in various development processes including Programmed Cell Death (PCD) associated development. However, the relationship between NAC family and PCD-associated cotton pigment gland development is largely unknown. In this study, we identified 150, 153 and 299 NAC genes in newly updated genome sequences of G. arboreum, G. raimondii and G. hirsutum, respectively. All NAC genes were divided into 8 groups by the phylogenetic analysis and most of them were conserved during cotton evolution. Using the vital regulator of gland formation GhMYC2-like as bait, expression correlation analysis screened out 6 NAC genes which were low-expressed in glandless cotton and high-expressed in glanded cotton. These 6 NAC genes acted downstream of GhMYC2-like and were induced by MeJA. Silencing CGF1(Cotton Gland Formation1), another MYC-coding gene, caused almost glandless phenotype and down-regulated expression of GhMYC2-like and the 6 NAC genes, indicating a MYC-NAC regulatory network in gland development. In addition, predicted regulatory mechanism showed that the 6 NAC genes were possibly regulated by light, various phytohormones and transcription factors as well as miRNAs. The interaction network and DNA binding sites of the 6 NAC transcription factors were also predicted. These results laid the foundation for further study of gland-related genes and gland development regulatory network.

Download Full-text

Conserved residues in the wheat (Triticum aestivum) NAM-A1 NAC domain are required for protein binding and when mutated lead to delayed peduncle and flag leaf senescence

BMC Plant Biology ◽

10.1186/s12870-019-2022-5 ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 1

Author(s):

Sophie A. Harrington ◽

Lauren E. Overend ◽

Nicolas Cobo ◽

Philippa Borrill ◽

Cristobal Uauy

Keyword(s):

Transcription Factors ◽

Leaf Senescence ◽

Protein Function ◽

Flag Leaf ◽

Missense Mutations ◽

In Planta ◽

Conserved Residues ◽

Nac Domain ◽

Nac Transcription Factors ◽

The Impact

Abstract Background NAC transcription factors contain five highly conserved subdomains which are required for protein dimerisation and DNA binding. Few residues within these subdomains have been identified as essential for protein function, and fewer still have been shown to be of biological relevance in planta. Here we use a positive regulator of senescence in wheat, NAM-A1, to test the impact of missense mutations at specific, highly conserved residues of the NAC domain on protein function. Results We identified missense mutations in five highly conserved residues of the NAC domain of NAM-A1 in a tetraploid TILLING population. TILLING lines containing these mutations, alongside synonymous and non-conserved mutation controls, were grown under glasshouse conditions and scored for senescence. Four of the five mutations showed a significant and consistent delay in peduncle senescence but had no consistent effects on flag leaf senescence. All four mutant alleles with the delayed senescence phenotype also lost the ability to interact with the homoeolog NAM-B1 in a yeast two-hybrid assay. Two of these residues were previously shown to be involved in NAC domain function in Arabidopsis, suggesting conservation of residue function between species. Three of these four alleles led to an attenuated cell death response compared to wild-type NAM-A1 when transiently over-expressed in Nicotiana benthamiana. One of these mutations was further tested under field conditions, in which there was a significant and consistent delay in both peduncle and leaf senescence. Conclusions We combined field and glasshouse studies of a series of mutant alleles with biochemical analyses to identify four residues of the NAC domain which are required for NAM-A1 function and protein interaction. We show that mutations in these residues lead to a gradient of phenotypes, raising the possibility of developing allelic series of mutations for traits of agronomic importance. We also show that mutations in NAM-A1 more severely impact peduncle senescence, compared to the more commonly studied flag leaf senescence, highlighting this as an area deserving of further study. The results from this integrated approach provide strong evidence that conserved residues within the functional domains of NAC transcription factors have biological significance in planta.

Download Full-text

A local regulatory network around three NAC transcription factors in stress responses and senescence in Arabidopsis leaves

The Plant Journal ◽

10.1111/tpj.12194 ◽

2013 ◽

Vol 75 (1) ◽

pp. 26-39 ◽

Cited By ~ 109

Author(s):

Richard Hickman ◽

Claire Hill ◽

Christopher A. Penfold ◽

Emily Breeze ◽

Laura Bowden ◽

...

Keyword(s):

Transcription Factors ◽

Stress Responses ◽

Regulatory Network ◽

Nac Transcription Factors

Download Full-text

Genome-Wide Analysis of NAC Transcription Factors in Sunflower (Helianthus Annuus), Their Comparative Phylogenetic Analysis and Association With Leaf Senescence

10.21203/rs.3.rs-860249/v1 ◽

2021 ◽

Author(s):

Sofia A. Bengoa Luoni ◽

Alberto Cenci ◽

Sebastian Moschen ◽

Salvador Nicosia ◽

Laura M. Radonic ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Transcription Factors ◽

Leaf Senescence ◽

Large Scale ◽

Gene Families ◽

Orthologous Group ◽

Specific Gene ◽

Significant Differential Expression ◽

Nac Transcription Factors ◽

Functional Relationships

Abstract Background Leaf senescence delay impacts positively in grain yield by maintaining the photosynthetic area during the reproductive stage and during grain filling. Therefore a comprehensive understanding of the gene families associated with leaf senescence is essential. NAC transcription factors (TF) form a large plant-specific gene family involved in regulating development, senescence, and responses to biotic and abiotic stresses. The main goal of this work was to identify sunflower NAC TF (HaNAC) and their association with senescence, studying their orthologous to understand possible functional relationships between genes of different species. ResultsTo clarify the orthologous relationships, we used an in-depth comparative study of four divergent taxa, in dicots and monocots, with completely sequenced genomes (Arabidopsis thaliana, Vitis vinifera, Musa acuminata and Oryza sativa). These orthologous groups provide a curated resource for large scale protein sequence annotation of NAC TF. From the 151 HaNAC genes detected in the latest version of the sunflower genome, 50 genes were associated with senescence traits. These genes showed significant differential expression in two contrasting lines according to an RNAseq assay. An assessment of overexpressing the Arabidopsis line for HaNAC001 (a gene of the same orthologous group of Arabidopsis thaliana ORE1) revealed that this line displayed a significantly higher number of senescent leaves and a pronounced change in development rate.ConclutionsThis finding suggests HaNAC001 as an interesting candidate to explore the molecular regulation of senescence in sunflower.

Download Full-text