scholarly journals Induction of Phytohormones and Differential Gene Expression in Citrus Flowers Infected by the Fungus Colletotrichum acutatum

2004 ◽  
Vol 17 (12) ◽  
pp. 1394-1401 ◽  
Author(s):  
Katherine A. Lahey ◽  
Rongcai Yuan ◽  
Jacqueline K. Burns ◽  
Peter P. Ueng ◽  
L. W. Timmer ◽  
...  
Keyword(s):  
Gene Expression ◽  
Differential Gene Expression ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Colletotrichum Acutatum ◽  
Young Fruit ◽  
Fruit Drop ◽  
Significant Difference ◽  
Genes Encoding ◽  
Differential Gene

Colletotrichum acutatum infects citrus petals and induces premature fruit drop and the formation of persistent calyces. The accumulation of hormones and other growth regulators, and differential gene expression in affected flowers and young fruit, was examined following fungal infection. Ethylene evolution increased threefold and indole-3-acetic acid (IAA) accumulation was as much as 140 times. Abscisic acid (ABA) levels showed no significant response. After infection, both trans- and cis-12-oxo-phytodienoic acid increased 8- to 10-fold. No significant difference of trans-jasmonic acid (JA) was observed in citrus flower petals or pistils. However, a fivefold increase of cis-JA was detected. The amount of salicylic acid (SA) was elevated twofold in affected petals, but not in pistils. Northern blot analyses revealed that the genes encoding ACC oxidase or ACC synthase, and 12-oxo-phytodienoic acid (12-oxo-PDA) reductase, were highly expressed in affected flowers. The genes encoding auxin-related proteins also were upregulated. Application of 2-(4-chlorophenoxy)-2-methyl-propionic acid (clofibrate; a putative auxin inhibitor), 2,3,5-triiodobenzolic acid (an auxin transport inhibitor), or SA after inoculation significantly decreased the accumulation of the gene transcripts of auxin-responsive, GH3-like protein and 12-oxo-PDA reductase, but resulted in higher percentages of young fruit retention. The results indicate that imbalance of IAA, ethylene, and JA in C. acutatum-infected flowers may be involved in symptom development and young fruit drop.

scholarly journals Genes for Hormone Biosynthesis and Regulation Are Highly Expressed in Citrus Flowers Infected with the Fungus Colletotrichum acutatum, Causal Agent of Postbloom Fruit Drop

2003 ◽  
Vol 128 (4) ◽  
pp. 578-583 ◽  
Author(s):  
Wei Li ◽  
Rongcai Yuan ◽  
Jacqueline K. Burns ◽  
L.W. Timmer ◽  
Kuang-Ren Chung
Keyword(s):  
Sweet Orange ◽  
Acc Oxidase ◽  
Colletotrichum Acutatum ◽  
Cdna Clones ◽  
Gene Expressions ◽  
Cell Wall Modification ◽  
Young Fruit ◽  
Fruit Drop ◽  
Genes Encoding ◽  
Differential Gene

Colletotrichum acutatum J. H. Simmonds infects citrus flower petals, causing brownish lesions, young fruit drop, production of persistent calyces, and leaf distortion. This suggests that hormones may be involved in symptom development. To identify the types of hormones, cDNA clones encoding proteins related to ethylene and jasmonate (JA) biosynthesis, indole-3-acetic acid (IAA) regulation, cell-wall modification, signal transduction, or fruit ripening were used to examine differential gene expressions in calamondin (Citrus madurensis Lour) and/or `Valencia' sweet orange (Citrus sinensis Osbeck) after C. acutatum infection. Northern-blot analyses revealed that the genes encoding 1-aminocyclopropane-1-carboxylate (ACC) oxidase and 12-oxophytodienoate required for ethylene and JA biosynthesis, respectively, were highly up-regulated in both citrus species. Both gene transcripts increased markedly in petals, young fruit and stigmas, but not in calyces. The transcripts of the genes encoding IAA glucose transferase and auxin-responsive GH3-like protein, but not IAA amino acid hydrolyase, also markedly increased in both species 5 days after inoculation. The expansin and chitinase genes were slightly up-regulated, whereas the senescence-induced nuclease and ß-galactosidase genes were down-regulated in calamondin. No differential expression of transcripts was detected for the genes encoding expansin, polygalacturonase, and serine-threonine kinase in sweet orange. As compared to the water controls, infection of C. acutatum increased ethylene and IAA levels by 3- and 140-fold. In contrast, abscisic acid (ABA) levels were not significantly changed. Collectively, the results indicate that infection by C. acutatum of citrus flowers triggered differential gene expressions, mainly associated with IAA, ethylene, and JA production and regulation, and increased hormone concentrations, consistent with the hypothesis of the involvement of phytohormones in postbloom fruit drop.

scholarly journals Low-P tolerance mechanisms and differential gene expression in contrasting wheat genotypes

2009 ◽  
Vol 44 (9) ◽  
pp. 1100-1105 ◽  
Author(s):  
Laize Fraga Espindula ◽  
Euclydes Minella ◽  
Carla Andréa Delatorre
Keyword(s):  
Gene Expression ◽  
Differential Gene Expression ◽  
Growth Stages ◽  
P Availability ◽  
Initial Growth ◽  
Tolerance Mechanisms ◽  
Wheat Seedlings ◽  
Wheat Genotypes ◽  
Genes Encoding ◽  
Differential Gene

The objectives of this study were to determine low-P tolerance mechanisms in contrasting wheat genotypes and to evaluate the association of these mechanisms to differential gene expression. Wheat seedlings of cultivars Toropi (tolerant to low-P availability) and Anahuac (sensitive) were evaluated. Seedlings were hydroponically grown in the absence or presence of P (1.0 mmol L-1) during three different time periods: 24, 120 and 240 hours. Free phosphate (Pi) and total P contents were measured in shoots and roots. The experiment's design was in randomized blocks with three replicates, each formed by ten plants. The relative expression of genes encoding the malate transporter TaALMT1 and the transcription factor PTF1 was evaluated. Phosphorus starvation beyond ten days increased the expression of TaALMT1 only in 'Toropi'. PTF1's expression was early induced in both genotypes under P starvation, but remained significant after ten days only in 'Toropi'. Shoot Pi concentration in 'Toropi' was independent from P availability; under starvation, 'Toropi' favored the maintenance of shoot Pi concentration. The low-P tolerance of Toropi cultivar at initial growth stages is mainly due to its ability to maintain constant the Pi shoot level.

scholarly journals Effect of Sprayable 1-MCP, AVG, and NAA on Ethylene Biosynthesis, Preharvest Fruit Drop, Fruit Maturity, and Quality of ‘Delicious’ Apples

HortScience ◽  
2008 ◽  
Vol 43 (5) ◽  
pp. 1454-1460 ◽  
Author(s):  
Rongcai Yuan ◽  
Jianguo Li
Keyword(s):  
Ethylene Production ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Naphthaleneacetic Acid ◽  
Fruit Softening ◽  
High Concentration ◽  
Oxidase Gene ◽  
Fruit Abscission ◽  
Fruit Drop ◽  
Significant Difference

Effects of naphthaleneacetic acid (NAA), aminoethoxyvinylglycine (AVG), and sprayable 1-methylcyclopropene (1-MCP) alone or in combination on fruit ethylene production, preharvest fruit drop, fruit quality, and fruit maturation were examined in ‘Delicious’ apples (Malus ×domestica Borkh.). 1-MCP and AVG + NAA, when applied 15 days before anticipated harvest (DBAH) for untreated control trees, more effectively delayed preharvest fruit drop than AVG or NAA used alone. However, there was no significant difference in ethylene production between fruit treated with 1-MCP or AVG + NAA and those treated by AVG. Two applications of NAA increased fruit ethylene production and fruit softening, whereas AVG inhibited NAA-enhanced fruit ethylene production and fruit softening. There was no significant difference in fruit ethylene production, fruit firmness, and fruit drop control between one and two applications of 1-MCP. The concentrations of 1-MCP did not affect the efficacy of 1-MCP when applied 15 DBAH, but high concentration of 1-MCP more effectively delayed preharvest fruit drop than low concentration of 1-MCP when applied 7 DBAH. Both AVG and 1-MCP suppressed expression of 1-aminocyclopropane-1-carboxylate (ACC) synthase gene MdACS1, ACC oxidase gene MdACO1, and polygalacturonase gene MdPG1 in fruit. Expression of ACS5A and MdACO1 but not MdACS1 in fruit abscission zones was decreased by AVG and 1-MCP. 1-MCP more effectively suppressed expression of MdPG2 in fruit abscission zones than AVG alone.

scholarly journals Transcriptome Profiling and Differential Gene Expression in Canine Microdissected Anagen and Telogen Hair Follicles and Interfollicular Epidermis

Genes ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 884
Author(s):  
Dominique J. Wiener ◽  
Kátia R. Groch ◽  
Magdalena A.T. Brunner ◽  
Tosso Leeb ◽  
Vidhya Jagannathan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Differential Gene Expression ◽  
Transcriptome Profiling ◽  
Structure And Function ◽  
Hair Follicles ◽  
Cellular Growth ◽  
Genes Encoding ◽  
Interfollicular Epidermis ◽  
Differential Gene ◽  
And Function

The transcriptome profile and differential gene expression in telogen and late anagen microdissected hair follicles and the interfollicular epidermis of healthy dogs was investigated by using RNAseq. The genes with the highest expression levels in each group were identified and genes known from studies in other species to be associated with structure and function of hair follicles and epidermis were evaluated. Transcriptome profiling revealed that late anagen follicles expressed mainly keratins and telogen follicles expressed GSN and KRT15. The interfollicular epidermis expressed predominately genes encoding for proteins associated with differentiation. All sample groups express genes encoding for proteins involved in cellular growth and signal transduction. The expression pattern of skin-associated genes in dogs is similar to humans. Differences in expression compared to mice and humans include BMP2 expression mainly in telogen and high KRT17 expression in the interfollicular epidermis of dogs. Our data provide the basis for the investigation of the structure and function of canine skin or skin disease and support the use of dogs as a model for human cutaneous disease by assigning gene expression to specific tissue states.

scholarly journals Preharvest Fruit Drop in Huanglongbing-affected ‘Valencia’ Sweet Orange

2019 ◽  
Vol 144 (2) ◽  
pp. 107-117 ◽  
Author(s):  
Lisa Tang ◽  
Shweta Chhajed ◽  
Tripti Vashisth
Keyword(s):  
Sweet Orange ◽  
Acc Oxidase ◽  
Pectate Lyase ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
Cell Wall Modification ◽  
Expression Levels ◽  
Fruit Drop ◽  
Genes Encoding ◽  
Calyx Abscission

For field-grown ‘Valencia’ sweet orange (Citrus sinensis) affected by Huanglongbing [HLB (Candidatus Liberibacter asiaticus (CLas)], trees that displayed more severe HLB symptoms (severe trees) had 74% fruit drop before harvest; however, the drop rate for less symptomatic trees (mild trees) was 45%. For mature fruit (3 weeks before harvest) still attached to the branches, 60% of them from severe trees were “loose fruit” [fruit detachment force (FT) < 6 kgf]. In contrast, only 13% of the attached fruit from the mild trees were loose. Overall, fresh weight and size of loose fruit were lower than “tight fruit” (FT > 6 kgf). Irrespective of the symptom levels of trees, the concentrations of glucose, fructose, and inositol in juice of loose fruit were the same or larger than those of tight fruit, suggesting that the shortage of carbohydrates is not the dominant cause of HLB-associated preharvest fruit drop. Expression levels of the cell wall modification genes encoding cellulase (endo-1,4-β-glucanase), polygalacturonase, and pectate lyase were greater in the calyx abscission zones of loose fruit compared to tight fruit, indicating that cell separation was occurring in the former at the time of collection. No differences in the expression levels of genes encoding the ethylene biosynthesis enzymes, including 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS) and ACC oxidase (ACO), and an ethylene-responsive transcription factor 1 (ERF1) were observed in tissues of loose and tight fruit. Interestingly, ACS, ACO, and EFR1 expressions were lower in calyx abscission zones and in leaves of the severe trees compared with those of mild trees, suggesting an ostensible, HLB-dependent reduction in ethylene biosynthesis and/or signaling close to harvest time. However, the role of ethylene in HLB-associated preharvest fruit drop remains to be determined. The results leave open the possibility of early ethylene production and action before the initiation of fruit abscission.

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