scholarly journals Expression of Gibberellin Metabolism Genes and Signalling Components in Dwarf Phenotype of Breadfruit (Artocarpus altilis) Plants Growing on Marang (Artocarpus odoratissimus) Rootstocks

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 634
Author(s):  
Yuchan Zhou ◽  
Steven J. R. Underhill
Keyword(s):  
Stem Elongation ◽  
Biosynthetic Gene ◽  
Dwarf Phenotype ◽  
Artocarpus Altilis ◽  
Della Proteins ◽  
Gibberellin Metabolism ◽  
Catabolic Genes ◽  
The Tropics ◽  
Insight Into ◽  
Size Controlling

Breadfruit (Artocarpus altilis) is a traditional staple tree crop throughout the tropics. The species is an evergreen tree 15–20 m; there are currently no size-controlling rootstocks within the species. Through interspecific grafting, a dwarf phenotype was identified in breadfruit plants growing on Marang (Artocarpus odoratissimus) rootstocks, which displayed ~60% reduction in plant height with ~80% shorter internodes. To gain insight into the molecular mechanism underlying rootstock-induced dwarfing, we investigated the involvement of gibberellin (GA) in reduction of stem elongation. Expression of GA metabolism genes was analysed in the period from 18 to 24 months after grafting. In comparison to self-graft and non-graft, scion stems on marang rootstocks displayed decrease in expression of a GA biosynthetic gene, AaGA20ox3, and increase in expression of a GA catabolic genes, AaGA2ox1, in the tested 6-month period. Increased accumulation of DELLA proteins (GA-signalling repressors) was found in scion stems growing on marang rootstocks, together with an increased expression of a DELLA gene, AaDELLA1. Exogenous GA treatment was able to restore the stem elongation rate and the internode length of scions growing on marang rootstocks. The possibility that GA deficiency forms a component of the mechanism underlying rootstock-induced breadfruit dwarfing is discussed.

scholarly journals Differential transcription pathways associated with rootstock-induced dwarfing in breadfruit (Artocarpus altilis) scions

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuchan Zhou ◽  
Steven J. R. Underhill
Keyword(s):  
Cell Wall ◽  
Cell Expansion ◽  
Stem Elongation ◽  
Redox Homeostasis ◽  
Signalling Pathways ◽  
Amino Acid Transporters ◽  
Biosynthetic Genes ◽  
Dwarf Phenotype ◽  
Artocarpus Altilis ◽  
Genes Encoding

Abstract Background Breadfruit (Artocarpus altilis) is a traditional staple tree crop throughout the tropics. Through interspecific grafting, a dwarf phenotype with over 50% reduction in plant height was identified when marang (Artocarpus odoratissimus) rootstocks were used. However, the molecular mechanism underlying the rootstock-induced breadfruit dwarfing is poorly understood. Results An RNA-sequencing study of breadfruit scions at 22 months after grafting identified 5409 differentially expressed genes (DEGs) of which 2069 were upregulated and 3339 were downregulated in scion stems on marang rootstocks compared to those on self-graft. The DEGs were predominantly enriched for biological processes involved in carbon metabolism, cell wall organization, plant hormone signal transduction and redox homeostasis. The down-regulation of genes encoding vacuolar acid invertases and alkaline/neutral invertases, was consistent with the decreased activity of both enzymes, accompanying with a higher sucrose but lower glucose and fructose levels in the tissues. Key genes of biosynthetic pathways for amino acids, lipids and cell wall were down regulated, reflecting reduction of sucrose utilisation for stem growth on dwarfing rootstocks. Genes encoding sugar transporters, amino acid transporters, choline transporters, along with large number of potassium channels and aquaporin family members were down-regulated in scion stems on marang rootstocks. Lower activity of plasma membrane H+-ATPase, together with the predominance of genes encoding expansins, wall-associated receptor kinases and key enzymes for biosynthesis and re-modelling of cellulose, xyloglucans and pectins in down-regulated DGEs suggested impairment of cell expansion. Signalling pathways of auxin and gibberellin, along with strigolacton and brassinosteroid biosynthetic genes dominated the down-regulated DEGs. Phenylpropanoid pathway was enriched, with key lignin biosynthetic genes down-regulated, and flavonoid biosynthetic genes upregulated in scions on marang rootstocks. Signalling pathways of salicylic acid, jasmonic acid, ethylene and MAPK cascade were significantly enriched in the upregulated DEGs. Conclusions Rootstock-induced disruption in pathways regulating nutrient transport, sucrose utilisation, cell wall biosynthesis and networks of hormone transduction are proposed to impair cell expansion and stem elongation, leading to dwarf phenotype in breadfruit scions. The information provides opportunity to develop screening strategy for rootstock breeding and selection for breadfruit dwarfing.

Biosynthesis of the uridine-derived nucleoside antibiotic A-94964: identification and characterization of the biosynthetic gene cluster provide insight into the biosynthetic pathway

2019 ◽  
Vol 17 (3) ◽  
pp. 461-466 ◽  
Author(s):  
Taro Shiraishi ◽  
Makoto Nishiyama ◽  
Tomohisa Kuzuyama
Keyword(s):  
Gene Cluster ◽  
In Silico ◽  
Biosynthetic Pathway ◽  
Gene Deletion ◽  
Biosynthetic Gene Cluster ◽  
Biosynthetic Gene ◽  
Identification And Characterization ◽  
Insight Into

The biosynthetic pathway of the uridine-derived nucleoside antibiotic A-94964 was proposed via in silico analysis coupled with gene deletion experiments.

GIBBERELLIN METABOLISM DURING STEM ELONGATION STIMULATED BY HIGH TEMPERATURE IN LETTUCE

2012 ◽  
pp. 259-264 ◽  
Author(s):  
M. Fukuda ◽  
S. Matsuo ◽  
K. Kikuchi ◽  
W. Mitsuhashi ◽  
T. Toyomasu ◽  
...  
Keyword(s):  
High Temperature ◽  
Stem Elongation ◽  
Gibberellin Metabolism

scholarly journals Gibberellin Signaling Repressor LlDELLA1 Controls the Flower and Pod Development of Yellow Lupine (Lupinus luteus L.)

2020 ◽  
Vol 21 (5) ◽  
pp. 1815
Author(s):  
Katarzyna Marciniak ◽  
Krzysztof Przedniczek
Keyword(s):  
Expression Profiles ◽  
Transcript Level ◽  
Lupinus Luteus ◽  
Flower Bud ◽  
Precise Control ◽  
Della Proteins ◽  
Fruit Setting ◽  
Pod Development ◽  
Yellow Lupine ◽  
Insight Into

Precise control of generative organ development is of great importance for the productivity of crop plants, including legumes. Gibberellins (GAs) play a key role in the regulation of flowering, and fruit setting and development. The major repressors of GA signaling are DELLA proteins. In this paper, the full-length cDNA of LlDELLA1 gene in yellow lupine (Lupinus luteus L.) was identified. Nuclear-located LlDELLA1 was clustered in a second phylogenetic group. Further analyses revealed the presence of all conserved motifs and domains required for the GA-dependent interaction with Gibberellin Insensitive Dwarf1 (GID1) receptor, and involved in the repression function of LlDELLA1. Studies on expression profiles have shown that fluctuating LlDELLA1 transcript level favors proper flower and pod development. Accumulation of LlDELLA1 mRNA slightly decreases from the flower bud stage to anther opening (dehiscence), while there is rapid increase during pollination, fertilization, as well as pod setting and early development. LlDELLA1 expression is downregulated during late pod development. The linkage of LlDELLA1 activity with cellular and tissue localization of gibberellic acid (GA3) offers a broader insight into the functioning of the GA pathway, dependent on the organ and developmental stage. Our analyses provide information that may be valuable in improving the agronomic properties of yellow lupine.

scholarly journals A Dwarf Phenotype Identified in Breadfruit (Artocarpus altilis) Plants Growing on Marang (A. odoratissimus) Rootstocks

Horticulturae ◽  
2019 ◽  
Vol 5 (2) ◽  
pp. 40
Author(s):  
Yuchan Zhou ◽  
Steven J. R. Underhill
Keyword(s):  
Biochemical Characterization ◽  
Soluble Sugars ◽  
Primary Proton ◽  
Dwarf Phenotype ◽  
Standard Size ◽  
Tropical Fruit ◽  
Artocarpus Altilis ◽  
Two Parameters ◽  
Staple Crop ◽  
Reduced Activity

Breadfruit (Artocarpus altilis) is a tropical fruit tree primarily grown as a staple crop for food security in Oceania. Significant wind damage has driven an interest in developing its dwarf phenotype. The presence of any dwarf breadfruit variety remains unknown. Little is known regarding the growth of the species on rootstocks. Here, we examined the phenotype of breadfruit plants growing on marang (Artocarpus odoratissimus) rootstocks within 18 months after grafting; we identified a rootstock-induced dwarf trait in the species. This dwarf phenotype was characterized by shorter stems, reduced stem thickness and fewer branches, with 73% shorter internode length, 51% fewer and 40% smaller leaves compared to standard size breadfruit plants. The height of breadfruit plants on marang rootstocks was reduced by 49% in 9 months, and 59% in 18 months after grafting. The results suggest marang rootstocks can be applied to breadfruit breeding program for tree vigor control. Further biochemical characterization showed plants on marang rootstocks displayed leaves without change of total chlorophyll content, but with lower total soluble sugars, and stems with reduced activity of plasma membrane H+-ATPase, a well-known primary proton pump essential for nutrient transport. The significance of the two parameters in rootstock dwarfing is discussed.

scholarly journals Unraveling a Tangled Skein: Evolutionary Analysis of the Bacterial Gibberellin Biosynthetic Operon

mSphere ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Ryan S. Nett ◽  
Huy Nguyen ◽  
Raimund Nagel ◽  
Ariana Marcassa ◽  
Trevor C. Charles ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Genetic Heterogeneity ◽  
Evolutionary History ◽  
Biosynthetic Gene Cluster ◽  
Evolutionary Analysis ◽  
Biosynthetic Gene ◽  
Ancestral Gene ◽  
Associated Bacteria ◽  
Microbe Interactions ◽  
Insight Into

ABSTRACT Gibberellin (GA) phytohormones are ubiquitous regulators of growth and developmental processes in vascular plants. The convergent evolution of GA production by plant-associated bacteria, including both symbiotic nitrogen-fixing rhizobia and phytopathogens, suggests that manipulation of GA signaling is a powerful mechanism for microbes to gain an advantage in these interactions. Although orthologous operons encode GA biosynthetic enzymes in both rhizobia and phytopathogens, notable genetic heterogeneity and scattered operon distribution in these lineages, including loss of the gene for the final biosynthetic step in most rhizobia, suggest varied functions for GA in these distinct plant-microbe interactions. Therefore, deciphering GA operon evolutionary history should provide crucial evidence toward understanding the distinct biological roles for bacterial GA production. To further establish the genetic composition of the GA operon, two operon-associated genes that exhibit limited distribution among rhizobia were biochemically characterized, verifying their roles in GA biosynthesis. This enabled employment of a maximum parsimony ancestral gene block reconstruction algorithm to characterize loss, gain, and horizontal gene transfer (HGT) of GA operon genes within alphaproteobacterial rhizobia, which exhibit the most heterogeneity among the bacteria containing this biosynthetic gene cluster. Collectively, this evolutionary analysis reveals a complex history for HGT of the entire GA operon, as well as the individual genes therein, and ultimately provides a basis for linking genetic content to bacterial GA functions in diverse plant-microbe interactions, including insight into the subtleties of the coevolving molecular interactions between rhizobia and their leguminous host plants. IMPORTANCE While production of phytohormones by plant-associated microbes has long been appreciated, identification of the gibberellin (GA) biosynthetic operon in plant-associated bacteria has revealed surprising genetic heterogeneity. Notably, this heterogeneity seems to be associated with the lifestyle of the microbe; while the GA operon in phytopathogenic bacteria does not seem to vary to any significant degree, thus enabling production of bioactive GA, symbiotic rhizobia exhibit a number of GA operon gene loss and gain events. This suggests that a unique set of selective pressures are exerted on this biosynthetic gene cluster in rhizobia. Through analysis of the evolutionary history of the GA operon in alphaproteobacterial rhizobia, which display substantial diversity in their GA operon structure and gene content, we provide insight into the effect of lifestyle and host interactions on the production of this phytohormone by plant-associated bacteria.

scholarly journals A Complex Signaling Cascade Governs Pristinamycin Biosynthesis in Streptomyces pristinaespiralis

2015 ◽  
Vol 81 (19) ◽  
pp. 6621-6636 ◽  
Author(s):  
Yvonne Mast ◽  
Jamil Guezguez ◽  
Franziska Handel ◽  
Eva Schinko
Keyword(s):  
Response Regulator ◽  
Receptor Gene ◽  
Signaling Cascade ◽  
Regulator Gene ◽  
Biosynthetic Gene ◽  
Content Type ◽  
Streptomyces Pristinaespiralis ◽  
Complex Signaling ◽  
Tetr Repressor ◽  
Insight Into

ABSTRACTPristinamycin production inStreptomyces pristinaespiralisPr11 is tightly regulated by an interplay between different repressors and activators. A γ-butyrolactone receptor gene (spbR), two TetR repressor genes (papR3andpapR5), three SARP (Streptomycesantibioticregulatoryprotein) genes (papR1,papR2, andpapR4), and a response regulator gene (papR6) are carried on the large 210-kb pristinamycin biosynthetic gene region ofStreptomyces pristinaespiralisPr11. A detailed investigation of all pristinamycin regulators revealed insight into a complex signaling cascade, which is responsible for the fine-tuned regulation of pristinamycin production inS. pristinaespiralis.

Arbuscular mycorrhizal fungal succession in a long-lived perennial

Botany ◽  
2014 ◽  
Vol 92 (4) ◽  
pp. 313-320 ◽  
Author(s):  
Miranda M. Hart ◽  
Monika Gorzelak ◽  
Diane Ragone ◽  
Susan J. Murch
Keyword(s):  
High Throughput Sequencing ◽  
Selective Pressure ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Fungal Communities ◽  
Artocarpus Altilis ◽  
Host Identity ◽  
Arbuscular Mycorrhizal Fungal ◽  
Insight Into

It is difficult to understand why arbuscular mycorrhizal (AM) fungal communities change over time. The role of host identity confounds our understanding of successional changes in AM fungal communities because hosts exert strong selective pressure on their root-associated microbes. In this study we looked at the AM fungi associated with a long-lived perennial breadfruit (Artocarpus altilis (Parkinson) Fosberg) to see how AM communities change over the life span of a single, long-lived host. Using 454 high-throughput sequencing, we found evidence that older trees had more AM fungal taxa than younger trees and were associated with different AM fungal communities, but these differences were not apparent early in the life cycle. Older trees were dominated by species of Rhizophagus, whereas younger trees and genets were dominated by species of Glomus. Some taxa were only detected in older trees (e.g., Funneliformis) or genets (e.g., Racocetra and Scutellospora), indicating that certain AM fungal taxa may serve as “indicators” of the successional age of the fungal community. These results provide important information about a poorly studied system and give insight into how AM communities change over longer time scales.

scholarly journals Linking global terrestrial CO<sub>2</sub> fluxes and environmental drivers: inferences from the Orbiting Carbon Observatory 2 satellite and terrestrial biospheric models

2021 ◽  
Vol 21 (9) ◽  
pp. 6663-6680
Author(s):  
Zichong Chen ◽  
Junjie Liu ◽  
Daven K. Henze ◽  
Deborah N. Huntzinger ◽  
Kelley C. Wells ◽  
...  
Keyword(s):  
Environmental Drivers ◽  
Co2 Uptake ◽  
Process Understanding ◽  
Large Spread ◽  
Ensemble Mean ◽  
Environmental Driver ◽  
The Tropics ◽  
The Relationship ◽  
Global Carbon ◽  
Insight Into

Abstract. Observations from the Orbiting Carbon Observatory 2 (OCO-2) satellite have been used to estimate CO2 fluxes in many regions of the globe and provide new insight into the global carbon cycle. The objective of this study is to infer the relationships between patterns in OCO-2 observations and environmental drivers (e.g., temperature, precipitation) and therefore inform a process understanding of carbon fluxes using OCO-2. We use a multiple regression and inverse model, and the regression coefficients quantify the relationships between observations from OCO-2 and environmental driver datasets within individual years for 2015–2018 and within seven global biomes. We subsequently compare these inferences to the relationships estimated from 15 terrestrial biosphere models (TBMs) that participated in the TRENDY model inter-comparison. Using OCO-2, we are able to quantify only a limited number of relationships between patterns in atmospheric CO2 observations and patterns in environmental driver datasets (i.e., 10 out of the 42 relationships examined). We further find that the ensemble of TBMs exhibits a large spread in the relationships with these key environmental driver datasets. The largest uncertainty in the models is in the relationship with precipitation, particularly in the tropics, with smaller uncertainties for temperature and photosynthetically active radiation (PAR). Using observations from OCO-2, we find that precipitation is associated with increased CO2 uptake in all tropical biomes, a result that agrees with half of the TBMs. By contrast, the relationships that we infer from OCO-2 for temperature and PAR are similar to the ensemble mean of the TBMs, though the results differ from many individual TBMs. These results point to the limitations of current space-based observations for inferring environmental relationships but also indicate the potential to help inform key relationships that are very uncertain in state-of-the-art TBMs.

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