Corrigendum: Phytoplasmas-The "Crouching Tiger" Threat of Australian Plant Pathology.

[This corrects the article DOI: 10.3389/fpls.2017.00599.].

In the original article, information for phytoplasmas in Table 1 did not fully reflect recent changes in taxonomy, or showed changes only as footnotes. Corrections have been made in the sections below and in Table 1.

Table 1

Taxonomic and biological information on phytoplasmas in Australia (empty cells denote the absence of available information).

16Sr group	“Candidatus Phytoplasma” name	Phytoplasma trivial name	Host plant species	Potential vectors	Location+	References*
II	australasiaea	Australian lucerne yellows	Medicago sativa, Carica papaya	Orosius argentatus, Austroagallia torrida, Orosius spp., Batracomorphus sp.	South Australia, New South Wales, Northern Territory	Padovan and Gibb, 2001*; Pilkington et al., 2003*; Yang et al., 2013
II		Bonamia pannosa little leaf	Bonamia pannosa		Northern Territory	Schneider et al., 1999; Padovan and Gibb, 2001
II		Cactus witches' broom	Carica papaya		Northern Territory	Padovan and Gibb, 2001
II		Cocky apple witches' broom	Planchonia careya		Queensland	Davis et al., 2001
II		Waltheria little leaf	Mitracarpus hirtus, Saccharum sp., Spermacocci sp., Waltheria indica, Carica papaya		Northern Territory	Schneider et al., 1999; Tran-Nguyen et al., 2000; Padovan and Gibb, 2001; Wilson et al., 2001
II	australasiae	Tomato big bud	Achyranthes aspera, Aeschynomene spp., Alysicarpus rugosus, Amaranthus sp., Apium graveolens, Arachis spp., Boeharvia sp., Brugmansia x candida, Capsicum annuum, Carica papaya, Catharanthus roseus, Cajanus cajan, Citrus paradisi, Crotalaria spp., Cenchrus ciliaris, Cichorium intybus, Cleome viscosa, Cucurbita maxima, Cynodon dactylon, Daucus carota, Emilia sonchifolia, Eragrostis falcata, Eriachne obtusa, Euphorbia milii, Evolvulus sp., Gerbera sp., Goodenia sp., Guizotia abyssinica, Ipomoea spp., Lactuca sativa, Lycopersicon esculentum, Macroptilium spp., Medicago sativa, Mucuna pruriens, Passiflora sp., Phlox sp., Physalis minima, Ptilotus distans, Rhynchosia minima, Saccharum sp., Sarcochilus hartmanii × S. falcatus, Sesamum indicum, Sida cordifolia, Lycopersicon esculentum, Solanum melongena, Stylosanthes scabra, Trifolium repens, Vigna spp., Vitis vinifera, Zinnia elegans,	Austroagallia torrida	Northern Territory, New South Wales, Queensland, Western Australia, Victoria	Gibb et al., 1995; Davis et al., 1997b; Gowanlock et al., 1998; De La Rue et al., 1999; Tran-Nguyen et al., 2000, 2003; Wilson et al., 2001*; Pilkington et al., 2004; Streten and Gibb, 2006
II	aurantifolia	Chickpea little leaf	Cicer arietinum		Western Australia	Saqib et al., 2005
II	australasiae	Papaya yellow crinkle	Carica papaya		Queensland	Gibb et al., 1996; White et al., 1998
II	australasiae	Papaya mosaic	Carica papaya		Queensland	Gibb et al., 1996; White et al., 1998
II		Tree medic witches' broom	Medicago arborea		South Australia	Yang et al., 2013
II		Pigeonpea phyllody	Cajanus cajan		South Australia	Yang et al., 2013
II		Pigeon pea little leaf	Arachis spp., Catharanthus roseus, Crotalaria spp., Desmodium triflorum, Indigofera sp., Macroptilium bracteatum Pterocaulon sp. Sesuvium portulacastrum, Stylosanthes spp., Vigna radiata		Northern Territory, Queensland, Torres Strait	Schneider et al., 1999; De La Rue et al., 2001; Padovan and Gibb, 2001; Wilson et al., 2001; Davis et al., 2003; Streten and Gibb, 2006
II-D	australasiae	Pale purple coneflower witches' broom	Echinacea pallida		Tasmania	Pearce et al., 2011
II-D	australasiae	Sweet potato little leaf	Alysicarpus vaginalis, Aphyllodium sp., Arachis spp., Cajanus marmoratus, Carica papaya, Catharanthus roseus, Centrosema pascuorum, Citrus sp., Cleome viscosa, Crotalaria spp., Cucurbita maxima, Cyanthillium spp., Desmodium spp., Emilia sonchifolia, Indigofera spp., Ipomoea batatas, Macroptilium gracile, Medicago sativa, Mitracarpus hirtus, Nicotiana tabacum, Pachyrhizus erosus, Physalis minima, Rhynchosia minima, Senna obtusifolia, Sesamum indicum, Stylosanthes ssp., Tridax procumbens, Vigna spp.	Austroagallia torrida, Orosius spp., Batracomorphus sp.	Torres Strait, Northern Territory, Western Australia, New South Wales	Gibb et al., 1995*; Liu et al., 1996; Davis et al., 1997b; Schneider and Gibb, 1997*; De La Rue et al., 1999, 2001; Padovan and Gibb, 2001; Wilson et al., 2001; Davis et al., 2003; Streten and Gibb, 2006; Tairo et al., 2006; Tran-Nguyen et al., 2012
XI-B		Cynodon white leaf	Cynodon dactylon, Dactyloctenium aegyptium		Northern Territory, Western Australia	Schneider et al., 1999; Tran-Nguyen et al., 2000; Blanche et al., 2003
XI-B		Sorghum grassy shoot	Dactyloctenium spp., Sorghum stipoideum, Whiteochloa spp., Chloris inflata, Whiteochloa cymbiformis		Western Australia, Northern Territory	Tran-Nguyen et al., 2000; Blanche et al., 2003
XII		Australian lucerne yellows	Medicago sativa		New South Wales	Getachew et al., 2007
XII		Papaya dieback	Carica papaya		Queensland	Gibb et al., 1996; White et al., 1998
XII-B	australiense	Pumpkin yellow leaf curl	Cucurbita maxima, C. moschata		Queensland, Western Australia, Northern Territory	Streten et al., 2005
XII-B	australiense	Cenchrus bunchy shoot	Cenchrus setiger		Western Australia	Tran-Nguyen et al., 2000
XII-B	australiense	Strawberry green petal disease	Fragaria x ananassa		Queensland	Padovan et al., 2000
XII-B	australiense	Strawberry lethal yellows	Fragaria x ananassa		Queensland	Padovan et al., 2000
XII-B	australiense	Australian grapevine yellowsb	Vitis vinifera, Carica papaya		South Australia, Queensland	Davis et al., 1997a,b; Davis and Sinclair, 1998; Davis et al., 2003
XXIIIc		Buckland Valley grapevine yellows	Vitis vinifera		Victoria	Constable et al., 2003; Streten and Gibb, 2006; Zhao and Davis, 2016
XXVd		Weeping tea tree witches' broom	Melaleuca spp.		Queensland	Davis et al., 2003; Zhao and Davis, 2016
XXXIII		Allocasuarina yellows	Allocasuarina muelleriana		South Australia	Gibb et al., 2003; Zhao and Davis, 2016
		Poinsettia branchinge	Euphorbia pulcherrima			Schneider et al., 1999
		Galactia little leaf	Galactia tenuiflora		Northern Territory	Schneider et al., 1999; Padovan and Gibb, 2001
		Sorghum bunchy shoot	Sorghum stipoideum			Tran-Nguyen et al., 2000
		Stylosanthes little leaf	Arachis pintoi, Carica papaya, Saccharum sp., Sesuvium portulacastrum, Stylosanthes scabra	Austroagallia torrida, Orosius spp., Batracomorphus sp.	Northern Territory, Queensland, New South Wales	Schneider et al., 1999; Tran-Nguyen et al., 2000; De La Rue et al., 2001; Padovan and Gibb, 2001; Davis et al., 2003; Gopurenko et al., 2016
		Sugarcane white leaf	Saccharum sp.		Western Australia, Queensland	Tran-Nguyen et al., 2000
		Vigna little leaf	Vigna lanceolata, Carica papaya, Tridax procumbens	Austroagallia torrida, Batracomorphus sp.	Northern Australia	Schneider et al., 1999; De La Rue et al., 2001; Padovan and Gibb, 2001
		Mundulla yellows diseasef	Eucalyptus camaldulensis, E. baxteri, E. leucoxylon		South Australia	Hanold et al., 2006
		Paulownia witches' broomg	Paulownia sp.		Western Australia	Bayliss et al., 2005

Denotes reference for vector data.

Location data are from the listed references but not every plant species was diseased in every location.

A new taxon, Ca. Phytoplasma australasia was proposed (White et al., .

Davis and Sinclair (.

Constable et al. (.

Zhao and Davis (.

This phytoplasma has not been found in economically important field crops.

Tentative data only for a phytoplasma etiology.

RFLP patterns showed high similarity to “Candidatus Phytoplasma australiense.”

Abstract

Phytoplasmas are insect-vectored bacteria that cause disease in a wide range of plant species. The increasing availability of molecular DNA analyses, expertise, and additional methods in recent years has led to a proliferation of discoveries of phytoplasma-plant host associations and in the numbers of taxonomic groupings for phytoplasmas. The widespread use of common names based on the diseases with which they are associated, as well as separate phenetic and taxonomic systems for classifying phytoplasmas based on variation at the 16S rRNA-encoding gene, complicates interpretation of the literature. We explore this issue and related trends through a focus on Australian pathosystems, providing the first comprehensive compilation of information for this continent, covering the phytoplasmas, host plants, vectors, and diseases. Of the 33 16Sr groups reported internationally, only groups II, XI, XII, XXIII, XXV, and XXXIII have been recorded in Australia and this highlights the need for ongoing biosecurity measures to prevent the introduction of additional pathogen groups. Many of the phytoplasmas reported in Australia have not been sufficiently well-studied to assign them to 16Sr groups so it is likely that unrecognized groups and sub-groups are present. Wide host plant ranges are apparent among well studied phytoplasmas, with multiple crop and non-crop species infected by some. Disease management is further complicated by the fact that putative vectors have been identified for few phytoplasmas, especially in Australia. Despite rapid progress in recent years using molecular approaches, phytoplasmas remain the least well-studied group of plant pathogens, making them a “crouching tiger” disease threat.

Issue 2: Complex taxonomic nomenclature, paragraphs 2 and 3

Second, as molecular methods became available, workers were able to group and phenetically classify phytoplasmas using restricted fragment length polymorphism (RFLP) analysis of a PCR amplified portion of the 16S rRNA gene with a defined set of restriction enzymes (Lee et al., 1998). The RFLP profiles generated for different phytoplasmas are generally consistent with sequence-based phylogenetic analyses of the 16S rRNA gene, particularly in the co-identification and grouping of related strains. The 33 16Sr groups currently defined each have a similarity of less than 85% compared with any representative phytoplasma from within an established 16Sr group (Zhao and Davis, 2016). Table 1 summarizes available information on the 16Sr groups reported in Australian studies. Of the 33 16Sr groups reported internationally, only groups II, XI, XII, XXIII, XXV, and XXXIII have been recorded in Australia and this highlights the need for ongoing biosecurity measures to prevent the introduction of additional pathogen groups.

Third, phytoplasmas are classified in the provisional genus “Candidatus Phytoplasma” (IRPCM, 2004). To date, there are 42 formally described species and ten potentially novel phytoplasma species (Davis et al., 2015). This number exceeds the current number of 16s rRNA groups because some of these groups contain several “Candidatus Phytoplasma” species. At least 100 subgroups are known (Dickinson and Hodgetts, 2013). According to Phytoplasma/Spiroplasma Working Team-Phytoplasma Taxonomy Group, a novel “Ca. Phytoplasma” species description should refer to a single, unique 16S rRNA gene sequence (>1,200 bp), and a strain can be recognized as a novel “Ca. Phytoplasma” species if its 16S rRNA gene sequence has <97.5% similarity to that of any previously described “Ca. Phytoplasma” species (Duduk and Bertaccini, 2011). Additional biological characters such as antibody specificity, host range and vector transmission specificity as well as genetic markers can also be used in an integrative taxonomy approach for species differentiation. Of the 42 recognized “Ca. Phytoplasma” species, only Ca. Phytoplasma aurantifolia, Ca. Phytoplasma australasiae and Ca. Phytoplasma australiense are reported in Australia (Table 1) but uncertainty exists because many papers appear without Ca. Phytoplasma names which are used consistently only in the case of the GenBank database.

The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.