Pectobacterium carotovorum subsp. brasiliense Causes Soft Rot and Death of Neobuxbaumia tetetzo in Zapotitlan Salinas Valley, Puebla, Mexico

Abstract

Neobuxbaumia tetetzo (Coulter) Backeberg (tetecho) is a columnar cactus endemic to Mexico. Tetecho plants, flowers, fruits, and seeds play an important role in the semiarid ecosystem, as they serve as a refuge and food for insects, bats, and birds, and are widely used by ethnic groups since pre-Hispanic times. Tetecho is affected by a soft rot that damages the whole plant and causes its fall and disintegration. Eight bacterial colonies of similar morphology were isolated from plants showing soft rot and inoculated in healthy tetecho plants, reproducing typical symptoms of soft rot 9 days after inoculation. Ten representative isolates were selected for phenotypic and genetic identification using 16s rDNA, IGS 16S-23S rDNA, and rpoS genes and for pathogenicity tests on several members of the cactus family and other plants. Based on the results, these bacterial isolates were identified as Pectobacterium carotovorum subsp. brasiliense. Inoculation of this bacteria caused soft rot in different cacti, fruits, leaves, and roots of other plants. This is the first report of the subspecies brasiliense of P. carotovorum causing soft rot and death in cacti in the world and the first report of this subspecies in Mexico.

Identification ofPectobacteriumspecies isolated from the soft rot of tetecho (Neobuxbaumia tetetzo), a columnar cactus, and associated metagenomics

“…Control plants inoculated with LB medium remained healthy during the time of the experiment (Fig 4). Taken together, these results confirm that strains A1, A3 and A8 recapitulate in vitro the disease symptoms observed in wild tetecho cacti, and they point to Pectobacterium as the ethiological agent, in agreement to previous observations [6].…”

“…We have preoviusly reported that P. brasiliense causes soft rot in N. tetetzo [6], but here we aimed to analyse new isolates in more detail. Using potatoes as baits to collect samples of three diseased and healty individuals we confirmed rot of potatos inoculated with infected cactus tissue while potatoes inoculated with healthy tissue did no rot.…”

Diseases Caused by Pectobacterium and Dickeya Species Around the World

“…atrosepticum has been isolated from potato, D. chrysanthemi from carrot and P. carotovorum from nopal (Opuntia cacti) (Oliveira et al 2003;González-Rodríguez et al 2005). Recently, P. brasiliense was described as the causative agent of soft rot of cactus crops in México (Mejía-Sánchez et al 2019). Ribas (2007) described pre-harvest field losses of potato crops in the field due to damage caused by Pectobacterium spp.…”

Host range and virulence diversity of Pectobacterium carotovorum subsp. brasiliense strain RDKLR infecting radish in India, and development of a LAMP-based diagnostics

“…The P. carotovora subsp. brasiliense is distributed worldwide and reported to cause blackleg of potato in South Africa (Van der et al, 2010), Kenya (Onkendi & Moleleki, 2014), Switzerland (De Werra et al, 2015), Turkey (Ozturk & Aksoy, 2016), Netherlands (van der Wolf et al, 2017), soft rot of pumpkin in Austria (Gottsberger & Huss, 2016), stem rot of tomato in Italy (Caruso et al, 2016), soft rot of cucumber (Meng et al, 2017) and radish in China (Liu et al, 2019), on squash and watermelon in Siberia (Zlatkovic et al, 2019) and Neobuxbaimia tetetzo in Mexico (Mejía‐Sánchez et al, 2019).…”