Two plant puroindolines colocalize in wheat seed and in vitro synergistically fight against pathogens.
Puroindolines, for years largely investigated for their involvement in wheat kernel hardness, have recently attracted attention thanks to their possible role as antimicrobial proteins. With the aim to enhance our knowledge of these proteins we studied their localization in the kernel, and their antimicrobial activity in vitro against six different bacterial strains. Immunolocalization showed that both the PINs are strongly concentrated in the aleurone layer, but also highly present in the endosperm. Interestingly we observed that puroindolines not only have the same spatial distribution in the kernel, they are also always found co-localized. Their co-localization suggests that they could cooperate in defending the plant against pathogens. We therefore tested antimicrobial activity of PINA and PINB, and a putative synergism between these proteins. The results showed that the two polypeptides can in vitro inhibit growth of all the bacteria tested; furthermore when combined together they are able to enhance each other's toxicity. In view of their antimicrobial activity and of their natural presence in Triticum aestivum wheat flour, puroindolines look promising antibacterial agents and thus deserve further studies aimed at establishing their possible future applications in fields of food and health care. Since PINs were still detectable in bakery products, these proteins may be promising tools in investigating natural ways of food preservation.
Capparelli
Rosanna
R
School of Biotechnological Sciences, University of Naples "Federico II", Via Università 133, 80055, Portici, Naples, Italy. capparel@unina.it.
Amoroso
Maria Grazia
MG
School of Biotechnological Sciences, University of Naples "Federico II", Via Università 133, 80055, Portici, Naples, Italy.
Palumbo
Daniela
D
School of Biotechnological Sciences, University of Naples "Federico II", Via Università 133, 80055, Portici, Naples, Italy.
Iannaccone
Marco
M
School of Biotechnological Sciences, University of Naples "Federico II", Via Università 133, 80055, Portici, Naples, Italy.
Faleri
Claudia
C
Dipartimento Scienze Ambientali, University of Siena, Via Mattioli 4, 53100, Siena, Italy.
Cresti
Mauro
M
Dipartimento Scienze Ambientali, University of Siena, Via Mattioli 4, 53100, Siena, Italy.
D001419:Bacteria / Q000187:drug effects / Q000254:growth & development; D005516:Food Microbiology; D005519:Food Preservation; D018506:Gene Expression Regulation, Plant; D008826:Microbial Sensitivity Tests; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D012639:Seeds / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology*; D013997:Time Factors; D014908:Triticum / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology*
D010940:Plant Proteins; C082942:puroindoline protein, Triticum aestivum