[49] Phytoplasmas have very small genomes, with extremely small amount of G and C nucleotides (sometimes as little as 23%, which is thought to be the lower threshold for a viable genome). [17][21] Leafhoppers lay increased numbers of eggs on AY-WB-infected plants, at least in part because of SAP11 production. 2003) and Ghana (Nipah et al. 2016) has, however, begun to overcome this hurdle. TENGU homologs have been identified in AY-group phytoplasmas. Similar diseases were reported in Togo (“kaincope” disease), Cameroon (“kribi” disease), and Ghana (“Cape St. Paul wilt” disease) by the early 1930s (Eden-Green 1997). Samayawardana Printers, Colombo, Sri Lanka, 336–341 pp. They also reported a list of palm species that were not known to be affected by LY, including Elaeis guineensis, Roystonea regia, Sabal palmetto, Thrinax radiata, and Washingtonia robusta. 2008). Infection triggers more axillary shoot production; the poinsettia plants thus produce more than a single flower. Hodgetts J, Boonham N, Mumford R, Harrison N, Dickinson M. 2008. [13] Transgenic expression of TENGU in Arabidopsis plants induced sterility in male and female flowers. But important progress related to identification of … Andoh-Mensah E, Ofosu-Budu GK (2012) Evaluation of coconut citrus intercropping systems in context of coconut lethal yellowing in Ghana. Dollet M, Macome F, Vaz A, Fabre S (2011) Phytoplasmas identical to coconut lethal yellowing phytoplasmas from Zambesia (Mozambique) found in a pentatomide bug in Cabo Delgado province. 2008; Brown and McLaughlin 2011). [16] SAP11 was found to induce stem proliferations and changes of leaf shapes of plants; the stem proliferations induced by SAP11 resemble witch's broom symptoms of AY-WB-infected plants. McCoy RE, Howard FW, Tsai JH, Donselman HM, Thomas DL, Basham RA, Atilano RA, Eskafi FM, Britt L, Collins ME (1983) Lethal yellowing of palms. For both LY and CILY at stage 3, the yellowed leaves eventually turn brown, desiccate, and hang down, forming a skirt around the trunk before falling and turning into telephone poles. Nevertheless, distinction between resistance to the vector transmission ability or to the phytoplasma host infection cannot be easily distinguished (Jarausch et al. Second Plantation Crop Symposium. 2008). 2014). [58] The actual number of taxonomic groups remains unclear; recent work on computer-simulated restriction digests of the 16Sr gene suggested up to 28 groups,[59] whereas others have proposed fewer groups, but more subgroups. [23][24][25][26] SAP11 is the first phytoplasma virulence protein for which plant targets and effector functions (i.e. 2013; Myrie et al. Phytoplasmas can also be spread via dodders (Cuscuta)[39] or by vegetative propagation such as the grafting of infected plant tissue onto a healthy plant. [2] The empirical use of antibiotics such as tetracycline was additionally employed. The gaps in the present knowledge of the diseases provide excellent opportunities for further research on these enigmatic plant pathogens. Harrison NA, Helmick EE, Elliot ML (2009) First report of a phytoplasma-associated lethal decline of, Harrison NA, Davis RE, Oropeza C, Helmick E, Narvaez M, Eden-Green S, Dollet M, Dickinson M (2014) ‘. Phytoplasma diseases are managed by the use of healthy planting material, removal of alternative weed hosts and chemical control of the insect vector. 2009; Arocha-Rosete et al. Management of these palm diseases relies on integrated approaches involving the use of resistant materials and cultural methods such as early detection and removal of affected palms. For example, the leafhopper Macrosteles quadrilineatus laid 30% more eggs on plants that expressing SAP11 transgenically than control plants, and 60% more eggs on plants infected with AY-WB. Olive phytoplasma diseases Why These phytoplasma diseases of olive came to our attention because two 'similar' reports were made approximately at the same time from Italy and Spain. Harrison NA, Cordova I, Richardson P, Dibonito R (1999) Detection and diagnosis of lethal yellowing. Symptoms of the disease include flattening and downward bending of leaflets giving the frond a ribbed or flaccid appearance. © Springer Nature Singapore Pte Ltd. 2018, Phytoplasmas: Plant Pathogenic Bacteria - I, http://www.fao.org/agriculture/crops/ thematic-sitemap/theme/pests/ipm/en/, http://eprints.nottingham.ac.uk/13953/1/575157.pdf, Oil Palm Research Institute, Coconut Programme, Council for Scientific and Industrial Research, Departamento de ProtecçãoVegetal, Faculdade de Agronomia e Engenharia Florestal, Centro de Investigación Científica de Yucatan, https://doi.org/10.1007/978-981-13-0119-3_9, 9.3 LY Phytoplasma Detection and Taxonomy, 9.8 Non-lethal Yellowing Diseases of Palms. Diseases with symptoms resembling those of LY were first reported in Africa at the beginning of the twentieth century. Symptoms appear very similar, but it cannot be said whether these diseases are caused by … 2012). The “bogia” coconut syndrome (BCS) phytoplasma is related to but distinct from all phytoplasmas described above; it appears to be closer to the lethal disease phytoplasma (Tanzania) (formally group 16SrIV) with only 96% identity (Kelly et al. In other places, such as in Africa, the vectors have so far been elusive, although putative vectors have been identified. Such subclades were informally proposed as three separate ‘Candidatus Phytoplasma’ species (IRPCM 2004), which were further supported by phylogenetic analysis of secA gene sequences (Hodgetts et al. Based on 16S rDNA RFLP and sequence analyses of the 16S rRNA gene, Mpunami et al. However, it is theorized that the stem-loop structures in PhREPS play a role in transcription termination or genome stability.[54]. Intercropping is widely used as an alternative means for managing a range of diseases. Symptoms of sweet potato little leaf phytoplasma on Catharanthus roseus, A flower of China Aster showing phyllody symptoms, A palm tree dying of lethal yellowing phytoplasma, A cabbage tree killed by Phytoplasma australiense, Witch's Broom disease of bamboo (Dendrocalamus strictus), CS1 maint: DOI inactive as of November 2020 (. Background. Plant Disease Vectors: Plant Disease Vectors are living or non-living micro-organism. 2002). Cite as. Contaldo N, Satta E, Zambon S Paltrinieri S, Bertaccini A (2016) Development and evaluation of different complex media for phytoplasma isolation and growth. Eds Waqas W, Faleiro R, Miller J, Thomas A. Springer, 287–314 pp. Eds Oropeza C, Howard FW, Ashburner GR. status[56] (used for bacteria that cannot be cultured). Subgroup16SrIV-B was found in coconuts in Mexico and in coconuts and Acrocomia aculeata palms in Honduras (Roca et al. There is no one symptom which predicts the presence of LYD but rather the symptoms can be considered as a syndrome involving a series of symptoms. Phytoplasma phylogenetics based on analysis of secA and 23S rRNA gene sequences for improved resolution of candidate species of ‘. In I. A nested PCR assay using R16 mF2/R16 mR1 and R16F2n/R16R2 primer pairs amplified products with approximate length of 1,250 bp from the symptomatic sugarcane samples. 1974; McCoy 1972). These diseases are associated with phytoplasmas belonging to 16Sr groups other than those in 16SrIV and 16SrXXII. 2007), respectively. In the host plants, phytoplasma multiply and spread only in the phloem tissue of various organs. Unlike lethal yellowing-like diseases, necrosis in unopened inflorescences and premature nut drop have not been observed for WCLWD. In: Proceedings of an International workshop on lethal yellowing–like diseases of coconut. In Mexico, management of LY is based on the use of coconut germplasm known to be resistant to LY (Zizumbo-Villarreal et al. History, distribution and epidemiology. In Asia, diseases with similar symptoms as LY have also been reported. Outlook about persepectives and future work to contain spread of these diseases are also reported. The phytoplasma associated with CYD shared 99% 16S rRNA identity with Bermuda grass white leaf phytoplasma related to ‘Ca. 2008). The phytoplasma recently described as BCS (Bogia coconut syndrome), phylogenetically related to the palm phytoplasma, is homologous with an emerging phytoplasma of another monocot: the banana wilt associated phytoplasma (BWAP), observed on cooking banana plants (Davis et al. [38], Phytoplasmas enter the insect body through the stylet, pass through the intestine, and then move to the hemolymph[38] and colonize the salivary glands: the entire process can take up to 3 weeks. Zizumbo-Villarreal D, Colunga-GarcíaMarín P, Fernández-Barrera M, Torres-Hernández N, Oropeza C (2008) Mortality of Mexican coconut germplasm due to lethal yellowing. In Ghana, a field practice called “slow down” has been implemented in an integrated control strategy based on early detection and prompt removal of diseased palms to control CSPWD spread (Danyo 2011). Subgroup16SrIV-F was found in Washingtonia robusta and Phoenix dactylifera palms in the USA (Ntushelo et al. The nucleic acid techniques based on polymerase chain reaction (PCR) procedures developed in the last 20 years are now Integrated management of diseases caused by fungi, phytoplasma and bacteria. Ashburner GR, Cordova I, Oropeza C, Illingworth R, Harrison NA (1996) First report of coconut lethal yellowing in Honduras. (1983) classified palms according to their level of susceptibility, and the most susceptible palms include Cocos nucifera, Phoenix dactylifera, and different Pritchardia species. Munguambe N, Timbrine R, Freire M, Gadaga S, Dias P, Do Rosario B, Pudivitr J, Pilet F (2013) Large scale management of coconut lethal yellowing disease in Mozambique. 1983), México (Oropeza and Zizumbo 1997), Belize (Eden-Green 1997), Honduras (Ashburner et al. Stage 1 of LY is recognized solely by premature nut fall (Harrison and Elliot 2005). In: Lethal Yellowing Research and Practical Aspects. Bila J, Högberg N, Mondjana A, Samils B (2015b). However, the phytoplasmas involved in these diseases are different from those that cause LYD/LY in Africa and the Caribbean region, and the diseases are generally not lethal. [34] The accumulation of mRNAs encoding class B MTFs, the transcription of which is positively regulated by class A and class E MTFs, is drastically decreased in Arabidopsis constitutively expressing PHYL1. Mpunami A, Tymon A, Jones P, Dickinson MJ (2000) Identification of potential vectors of the coconut lethal disease phytoplasma. This service is more advanced with JavaScript available, Phytoplasmas: Plant Pathogenic Bacteria - I Palms are found in tropical and subtropical areas of the world and have significant economic and ecological importance. Coconut yellowing disease. 2006). After yellowing, the affected branches dry, resulting in plants with mixed dead and still green branches. 1972; Heinze et al. Medhi A, Baranwal VK, Babu MK, Deepthi P (2012) Sequence analysis of 16S rRNA and secA genes confirms the association of 16SrI-B subgroup phytoplasma with oil palm (. Many phytoplasma-infected plants develop a bushy or "witch's broom" appearance due to changes in their normal growth patterns. Gundersen DE, Lee I-M, Rehner SA, Davis RE, Kingsbury DT (1994) Phylogeny of mycoplasmalike organisms (phytoplasmas): a basis for their classification. [27][28], The AY-WB phytoplasma effector SAP54 was shown to induce virescence and phyllody when expressed in plants and homologs of this effector were found in at least three other phytoplasmas. ISSN : 0972-0499 DOI : 10.5958/2249-880x.2017.00001.9 Alhudaib K, Arocha Y, Wilson M, Jones P (2007) “Al-Wijam”, a new phytoplasma disease of date palm in Saudi Arabia. Methods of experimental transmission. Tymon et al. 2008). Eds Eden-Green SJ, Ofori F, Natural Resources Institute, Chatham, United Kingdom, 221–234 pp. This IPM program includes (a) monitoring to detect palms with early LY symptoms, (b) elimination of these palms as soon as they are detected, (c) immediate replanting, and (d) weeding. Typical LYD symptoms progression in Mozambique: premature nut drop (a); progressive yellow discoloration from the oldest to the youngest leaves followed by skirt-shaped brown discoloration (necrosis) of the older leaves (b, c); rotting and death of the apical meristem/spear leaves (d) followed by wilting and collapse of the entire crown (e) leaving an empty stem (f), Sequence of symptom development of CSPWD in Ghana. Lebrun P, Baudouin L, Myrie W, Berger A, Dollet M (2008) Recent lethal yellowing outbreak: why is the Malayan yellow dwarf coconut no longer resistant in Jamaica. Myrie W, Oropeza C, Sáenz L, Harrison N, Roca MM, Córdova I, Ku S, Douglas L (2011) Reliable improved molecular detection of coconut lethal yellowing phytoplasma and reduction of associated disease through field management strategies. P. palmicola’ (Bila et al. Plant diseases are caused by harmful microorganisms such as virus and bacteria. [22] Phytoplasmas cannot survive in the external environment and are dependent upon insects such as leafhoppers for transmission to new (healthy) plants. Ultrathin sections of phloem tissue from plants with suspected phytoplasma-infections were also studied. The diseases are vectored by insects, such as Haplaxius crudus, which transmits the lethal yellowing phytoplasma in Florida. Indirect potential insect vector screening through membrane-feeding assay followed by PCR testing for phytoplasma detection on the media (Tanne et al. Yellowing of LY-affected palms does not show yellowing of fronds until stage 3 of the disease. (1989). Likewise, in Tanzania the lethal disease (LD) has caused extensive losses to coconut plantations and is now the main limiting factor of coconut production throughout the coastal belt of the mainland (Schuiling et al. Nested PCR and sequence analyses of the 16S rRNA and the secA genes confirmed the presence of the CILY phytoplasma in 216 out of 296 (73%) of the N. curta specimens, which suggested N. curta as a potential vector for the CILY phytoplasma (Kwadjo et al. Several economically relevant phytoplasma-associated diseases are described together with an update of phytoplasma taxonomy and major biological and molecular features of phytoplasmas. Specific control measures reported for diseases associated with ‘Ca. Razin S (2007) Molecular biology and genomics of. (Mpunami et al. Based on our years of experience and the latest science, APHIS developed a list of 59 pests and diseases that could pose a significant risk to U.S. food and agriculture resources. Phytoplasmas lack many genes encoding standard metabolic functions and have no functioning homologous recombination pathway, but they do have a sec transport pathway. An emerging problem in the Pacific Northwest USA is a ‘purple-top’ disease caused by a clover proliferation group phytoplasma vectored primarily, but not exclusively, by beet leafhopper, Circulifer tenellus (Baker) (Crosslin et al., 2005). Female flower production declines and the palm becomes unproductive. [53], Phytoplasma genomes contain large numbers of transposons and insertion sequences and also contain a unique family of repetitive extragenic palindromes termed PhREPS for which no role is known. 2011) and group 16SrXXII, suggesting that this phytoplasma is part of the lethal yellowing disease cluster. In 2013, a yellow decline was observed also on royal palms (Roystonea regia) (Naderali et al. Phytoplasmas can infect and cause various symptoms in more than 700 plant species. (2007) Effective elimination of sweet potato little lead by cryotherapy of shoot tips. 2014). 2009), and T. radiata (Narvaez et al. Transmission studies similar to those by Howard (1995) testing H. crudus as a vector have been performed outside Florida without success so far. The vector for CSPWD phytoplasma in Ghana is still unknown despite massive surveys that resulted in over 12,500 specimens representing 203 species of 19 families (Pilet et al. Part of Springer Nature. 2009). Before the molecular era, the diagnosis of phytoplasma-caused diseases was difficult because the organisms could not be cultured. Premature dropping of nuts (a); toppling of crown (c); blackening of inflorescence (b); progressive yellowing of fronds (d–e); bare trunks or telephone poles (g–h); a severely devastated farm (i) (Courtesy of J. Nkansah-Poku). [13] TENGU was suggested to inhibit both auxin- and jasmonic acid-related pathways, thereby affecting plant development. Martinez RT, Narvaez M, Fabre S, Harrison NA, Oropeza C, Dollet M, Hichez E (2008) Coconut lethal yellowing on the southern coast of the Dominican Republic is associated with a new 16SrIV group phytoplasma. 2014), Mexico (Narvaez et al. Phytoplasmas are most prevalent in tropical and subtropical regions. Phytoplasmas can have varying effects on their insect hosts; examples of both reduced and increased fitness have been noted. Although no transmission studies have been carried out testing Cedusa insects, this occurrence supports the potential existence of other vectors of LY phytoplasmas. The Mozambican and Nigerian LYD phytoplasma groups have been described as ‘Ca. The many gaps that exist in the present understanding of the diseases provide exciting opportunities for further research. After several growth cycles, the plants become … Palm Diseases Caused by Phytoplasmas: Lethal Yellowing and Texas Phoenix Palm Decline Monica L. Elliott and Nigel A. Harrison University of Florida, IFAS, Fort Lauderdale Research and Education Center July 2007 Until recently, the only Florida palm disease caused by a phytoplasma was lethal yellowing. Intercropping coconut with other crops have failed to lower the disease incidence, but provided an alternative source of income as insurance against CSPWD in Ghana (Andoh-Mensah and Ofosu-Budu 2012) and LD in Tanzania (Oleke et al. Tanne E, Boudon-Padieu E, Clair D, Davidovich M, Melamed S, Klein M (2001) Detection of phytoplasma by polymerase chain reaction of insect feeding medium and its use in determining vectoring ability. [8], Tissue culture can be used to produce healthy clones of phytoplasma-infected plants. The main production zone of coconut in Asia/Oceania was not affected by lethal yellowing diseases associated with one of the phytoplasmas of the palm groups (i.e., 16SrIV and 16SrXXII) during the twentieth century. Johnson WH (1918) Annual Report of the Agricultural Department of Southern Provinces, Nigeria for the year 1917. The identification of the phytoplasmas agent of LY was based on (a) observations by transmission electron microscopy (TEM) of their presence in phloem vessels of affected palms (Beakbane et al. Definition Phytoplasmas are obligate bacterial parasites of plant phloem tissue and of the insect vectors that are involved in their plant-to-plant transmission SAP11 effectors are identified in a number of divergent phytoplasmas and these effectors also interact with TCPs and modulate plant defenses. Sequences from the Mozambique LY phytoplasma shared 99.0–99.6% identity with those of CSPWD and CILY phytoplasmas but less than 97.5% identity with reference strains from all previously described ‘Candidatus Phytoplasma’ species. [8] Phytoplasma taxonomic groups are based on differences in fragment sizes produced by restriction digests of 16S ribosomal RNA gene sequences (RFLPs) or by comparisons of DNA sequences from 16s/23s spacer regions. Although phytoplasmas have recently been reported to be grown in a specific artificial medium, experimental repetition has yet to be reported. The country hosts the International Coconut Genebank for Africa and the Indian Ocean, and the spread of the disease to new coconut-growing areas is of great concern. Nejat N, Sijam K, Abdullah SNA Vadamalai G., Dickinson M (2009b) Phytoplasmas associated with disease of coconut in Malaysia are from two different phylogenetic groups and occur in other plant species. The expression of genes involved in maintaining the apical meristem or in the development of floral organs is altered in the morphologically affected floral organs of phytoplasma-infected plants.[9][10]. Lee I-M, Davis RE, Gundersen-Rindal, DE (2000) Phytoplasmas: phytopathogenic mollicutes. In Mozambique, Bila et al. [A Ciancio; K G Mukerji;] -- This book is about stone fruit and apple diseases, grapevine and fruit crops phytoplasma, Phytophthora on citrus, chestnut diseases, esca complex on grapevine and Rosellinia necatrix root rot. 2013). Several economically relevant phytoplasma-associated diseases are described together with an update of phytoplasma taxonomy and major biological and molecular features of phytoplasmas. 2016). More recent techniques allow infection levels to be assessed. evidence of benefit for the pathogen) were identified. Phytoplasma: diseases, disease pictures, symptoms, classification, databases, detection and identification, phylogeny, taxonomy, and Genomics. The first scientific report of the disease was made at the close of the nineteenth century in Jamaica. Mpunami A, Tymon A, Jones P, Dickinson M (1999) Genetic diversity in the coconut lethal yellowing disease phytoplasma of East Africa. Modification in primary and secondary metabolic pathway genes is altered upon phytoplasma infestation. Gurr GM, Johnson AC, Ash GJ, Wilson BAL, Ero MM, Pilotti CA, Dewhurst CF, You MS (2016) Coconut lethal yellowing diseases: a phytoplasma threat to palms of global economic and social significance. Nkansah-Poku J, Dery SK, Philippe R (2005) Reduction of spread of CSPWD of coconut by insecticidal hot-fogging and removal of diseased palms. [43], Tetracyclines are bacteriostatic to phytoplasmas. Kalimantan wilt disease of coconut was first reported in Indonesia by farmers in 1978, and an outbreak was observed in 1988 (Warokka et al. Tahir Awan M.Sc. Phytoplasma diseases of vegetable crops are characterized by symptoms … However, in these regions the phytoplasmas involved are different from those associated with diseases in Africa and the Caribbean region. (1998) showed that the phytoplasmas causing “awka” disease in Nigeria (LDN) and Cape St. Paul wilt disease (CSPWD) in Ghana were associated with either the same or very closely related strains. Apart from ‘Ca. comprehensive list see McCoy et al. Symptoms similar to those of LY in coconuts have been observed in more than 50 other palm species (McCoy et al. A range of lethal yellowing-type diseases have been reported from Asia. Naderali N, Nejat N, Vadamalai G, Tan YH (2013) First report of two distinct phytoplasma species, ‘. [13][14] Surprisingly, the N-terminal 11 amino acid region of the mature protein triggers symptom development in Nicotiana benthamiana plants. Infection of phytoplasma is known to cause disease on … However, the same study failed to confirm any of the pantatomids previously tested as harboring LYD phytoplasma. 2011) and in Phoenix canariensis, Phoenix dactylifera, P. reclinata, P. roebelenii, P. sylvestris, Syagrus romanzoffiana, Butiagrus “nabonnandii” (Butia odorata × S. romanzoffiana), and Sabal palmetto palms in the USA. The vector of the disease is unknown, but the plant hopper Proutista moesta and the lace bug Stephanitis typica are considered the likely candidates (Wejisekara et al. 2016), Belize, Cuba, Honduras, Jamaica, St. Kitts and Nevis (Myrie et al. 2013). In 1967, phytoplasmas were discovered in ultrathin sections of plant phloem tissue and were termed mycoplasma-like organisms due to their physiological resemblance The organisms were r… Later studies using PCR have shown that phytoplasmas in H. crudus belong to the 16SrIV group (Harrison and Oropeza 1997). In: Current Advances in Coconut Biotechnology. 1998; Harrison and Oropeza 2008). Examples of ornamental plants in which ... (virescence). [7] A typical phytoplasma is pleiomorphic or filamentous in shape and is less than 1 μm in diameter. 2014; Bila et al. Similar devastation occurred in Ghana, causing the near collapse of the once vibrant coconut industry in the Volta Region, one of the main coconut-producing areas of Ghana, as well as destroying thousands of hectares of palms in the Western and Central Regions of Ghana (Ofori and Nkansah-Poku 1997; Nkansah-Poku et al.
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