Systematic review of defense responses against Phytophthora and strategies to manage Phytophthora diseases in citrus.

Phytophthora spp. are the causal agents of gummosis or foot rot, fibrous root rot, and fruit brown rot diseases that affect the roots, trunk, and fruits of citrus trees, causing severe economic losses. This work presents an updated systematic review addressing the defence responses in citrus against Phytophthora and the strategies to manage Phytophthora diseases.

High-Quality Draft Genome Sequence Resources of Eight Strains Isolated from Citrus, Coffee, Plum, and Hibiscus in South America.

subsp. , once confined to South America and infecting mainly citrus and coffee plants, has been found to be associated with other hosts and in other geographic regions. We present high-quality draft genome sequences of subsp.

Recurrent water deficit causes alterations in the profile of redox proteins in citrus plants.

Plant acclimation to recurrent stress involves profound alterations in multiple genetic, metabolic and physiological processes. Stressful conditions usually implicate imbalance in reactive oxygen species (ROS) production and removal rates, which may lead to oxidative stress. However, the primary cellular targets of oxidative stress and their relevance in plant acclimation to abiotic stresses remains poorly characterized.

Recurrent water deficit causes epigenetic and hormonal changes in citrus plants.

The present study evaluated the physiological, molecular and hormonal parameters from scion/rootstock interaction of citrus plants during recurrent water deficit. Responses of the Valencia (VO) scion variety grafted on two rootstocks with different soil water extraction capacities, Rangpur Lime (RL) and Sunki Maravilha (SM), during three successive periods of water deficit: plants exposed to a single episode of water deficit (WD1) and plants exposed to two (WD2) and three (WD3) recurrent periods of WD were compared. The combinations VO/RL and VO/SM presented polymorphic alterations of epigenetic marks and hormonal (i.

Differential accumulation of flavonoids and phytohormones resulting from the canopy/rootstock interaction of citrus plants subjected to dehydration/rehydration.

Water scarcity can elicit drastic changes in plant metabolic and hormonal regulation, which may be of fundamental importance to stress tolerance. The study of plant the metabolic alterations in response to water deficit, especially the effects of the rootstocks level, is important to elucidate the mechanisms associated to drought tolerance. To verify the influence of rootstock and grafting on the tolerance to drought in citrus plants, we analyzed the growth, phytohormone levels and flavonoid profiles in grafted and ungrafted citrus plants subjected to different soil water regimes on plant status (well-watered, moderate drought and severe drought and rehydrated) under field conditions.

A L-type lectin gene is involved in the response to hormonal treatment and water deficit in Volkamer lemon.

Combination of biotic and abiotic stress is a major challenge for crop and fruit production. Thus, identification of genes involved in cross-response to abiotic and biotic stress is of great importance for breeding superior genotypes. Lectins are glycan-binding proteins with a functions in the developmental processes as well as in the response to biotic and abiotic stress.

Expression of the citrus CsTIP2;1 gene improves tobacco plant growth, antioxidant capacity and physiological adaptation under stress conditions.

Overexpression of the citrus CsTIP2;1 improves plant growth and tolerance to salt and drought stresses by enhancing cell expansion, H O detoxification and stomatal conductance. Tonoplast intrinsic proteins (TIPs) are a subfamily of aquaporins, belonging to the major intrinsic protein family. In a previous study, we have shown that a citrus TIP isoform, CsTIP2;1, is highly expressed in leaves and also transcriptionally regulated in leaves and roots by salt and drought stresses and infection by 'Candidatus Liberibacter asiaticus', the causal agent of the Huanglongbing disease, suggesting its involvement in the regulation of the flow of water and nutrients required during both normal growth and stress conditions.

Survival strategies of citrus rootstocks subjected to drought.

Two citrus rootstocks, Rangpur lime (RL) and Sunki Maravilha mandarin (SM), were analyzed either ungrafted or grafted with their reciprocal graft combinations or with shoot scions of two commercial citrus varieties: Valencia orange (VO) and Tahiti acid lime (TAL). All graft combinations were subjected to distinct watering regimes: well-watered, severe drought and rehydration. Growth and water relation parameters, gas exchange as well as sugar and hormone profiles were determined.

Citrus tristeza virus (CTV) Causing Proteomic and Enzymatic Changes in Sweet Orange Variety "Westin".

Citrus Tristeza disease, caused by CTV (Citrus tristeza virus), committs citrus plantations around the world and specifically attacks phloem tissues of the plant. The virus exists as a mixture of more or less severe variants, which may or may not cause symptoms of Tristeza. The objective of this study was to analyze the changes caused by CTV in the proteome of stems of sweet orange, as well as in the activity and gene expression of antioxidant enzymes.

Comparative study of the protein profiles of Sunki mandarin and Rangpur lime plants in response to water deficit.

Background: Rootstocks play a major role in the tolerance of citrus plants to water deficit by controlling and adjusting the water supply to meet the transpiration demand of the shoots. Alterations in protein abundance in citrus roots are crucial for plant adaptation to water deficit. We performed two-dimensional electrophoresis (2-DE) separation followed by LC/MS/MS to assess the proteome responses of the roots of two citrus rootstocks, Rangpur lime (Citrus limonia Osbeck) and 'Sunki Maravilha' (Citrus sunki) mandarin, which show contrasting tolerances to water deficits at the physiological and molecular levels.

Recombinant β-1,3-1,4-glucanase from Theobroma cacao impairs Moniliophthora perniciosa mycelial growth.

In this work, we identified a gene from Theobroma cacao L. genome and cDNA libraries, named TcGlu2, that encodes a β-1,3-1,4-glucanase. The TcGlu2 ORF was 720 bp in length and encoded a polypeptide of 239 amino acids with a molecular mass of 25.

Ectopic expression of a fruit phytoene synthase from Citrus paradisi Macf. promotes abiotic stress tolerance in transgenic tobacco.

Abscisic acid (ABA) is an important regulator of plant responses to environmental stresses and an absolute requirement for stress tolerance. Recently, a third phytoene synthase (PSY3) gene paralog was identified in monocots and demonstrated to play a specialized role in stress-induced ABA formation, thus suggesting that the first committed step in carotenogenesis is a key limiting step in ABA biosynthesis. To examine whether the ectopic expression of PSY, other than PSY3, would similarly affect ABA level and stress tolerance, we have produced transgenic tobacco containing a fruit-specific PSY (CpPSY) of grapefruit (Citrus paradisi Macf.

Evaluation of the allergenicity potential of TcPR-10 protein from Theobroma cacao.

Background: The pathogenesis related protein PR10 (TcPR-10), obtained from the Theobroma cacao-Moniliophthora perniciosa interaction library, presents antifungal activity against M. perniciosa and acts in vitro as a ribonuclease. However, despite its biotechnological potential, the TcPR-10 has the P-loop motif similar to those of some allergenic proteins such as Bet v 1 (Betula verrucosa) and Pru av 1 (Prunus avium).

Transcriptomics and systems biology analysis in identification of specific pathways involved in cacao resistance and susceptibility to witches' broom disease.

This study reports on expression analysis associated with molecular systems biology of cacao-Moniliophthora perniciosa interaction. Gene expression data were obtained for two cacao genotypes (TSH1188, resistant; Catongo, susceptible) challenged or not with the fungus M. perniciosa and collected at three time points through disease.

Unraveling new genes associated with seed development and metabolism in Bixa orellana L. by expressed sequence tag (EST) analysis.

The tropical tree Bixa orellana L. produces a range of secondary metabolites which biochemical and molecular biosynthesis basis are not well understood. In this work we have characterized a set of ESTs from a non-normalized cDNA library of B.

ESTs from Seeds to Assist the Selective Breeding of Jatropha curcas L. for Oil and Active Compounds.

We report here on the characterization of a cDNA library from seeds of Jatropha curcas L. at three stages of fruit maturation before yellowing. We sequenced a total of 2200 clones and obtained a set of 931 non-redundant sequences (unigenes) after trimming and quality control, ie, 140 contigs and 791 singlets with PHRED quality ≥10.

Isolation and purification of RNA from tissues rich in polyphenols, polysaccharides, and pigments of annatto (Bixa orellana L.).

The tropical plant Bixa orellana L. (annatto) produces an array of natural products, including the pigment bixin used in the food and cosmetics industries. In order to understand the biochemical and molecular basis of the biosynthesis of these natural products, a reliable method for isolating high yields of high-quality RNA is required.

Comparative analysis of expressed genes from cacao meristems infected by Moniliophthora perniciosa.

Background And Aims: Witches' broom disease is caused by the hemibiotrophic basidiomycete Moniliophthora perniciosa, and is one of the most important diseases of cacao in the western hemisphere. Because very little is known about the global process of such disease development, expressed sequence tags (ESTs) were used to identify genes expressed during the Theobroma cacao-Moniliophthora perniciosa interaction.

Methods: Two cDNA libraries corresponding to the resistant (RT) and susceptible (SP) cacao-M.

Characterization of necrosis and ethylene-inducing proteins (NEP) in the basidiomycete Moniliophthora perniciosa, the causal agent of witches' broom in Theobroma cacao.

The hemibiotrophic basidiomycete Moniliophthora perniciosa causes witches' broom disease of Theobroma cacao. Analysis of the M. perniciosa draft genome led to the identification of three putative genes encoding necrosis and ethylene-inducing proteins (MpNEPs), which are apparently located on the same chromosome.

Isolation and purification of functional total RNA from different organs of cacao tree during its interaction with the pathogen Crinipellis perniciosa.

Witches' broom disease, caused by Crinipellis perniciosa, is one of the major fungal diseases causing severe losses to cacao tree (Theobroma cacao L.) plantations in South America. One of the challenges associated with the understanding of the cacao and Crinipellis interaction in genomic studies is the isolation of intact nucleic acids.