The Unique Properties of an Edible, Analeptic Fungicide

ITQB - SCAN Seminar

Title: The Unique Properties of an Edible, Analeptic Fungicide

Speaker: Ricardo Boavida Ferreira

Affiliation: Disease and Stress Biology Laboratory

Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa
Instituto Superior de Agronomia, Universidade Técnica de Lisboa
CEV- Biotecnologia das Plantas, S.A.
 

Abstrat:

The continuous increment in world population and decrease in farming land, associated to an increasing public concern over the use of chemical fungicides has led to an intensive search for new and non-toxic ways for disease control and for crop production increments. The era for the chemical synthesis of potentially active compounds seems to be over. Development of nontoxic fungicides and plant growth promoters is therefore imperative.

Blad is a 20 kDa polypeptide, composed of 173 amino acid residues, that occurs naturally in Lupinus plants during a short phase of their development. It is a stable breakdown product of β-conglutin catabolism, their major seed storage protein. Blad is a lectin that binds in a very strong manner to chitin and displays N-acetyl-D-glucosaminidase and chitosanase catalytic activities. It is highly susceptible to proteolytic attack but otherwise extremely resistant to denaturation, withstanding temperatures above 100 ºC and treatments with strong acids (as long as they don´t cleave peptide bonds), bases, detergents, organic solvents or ultraviolet radiation, without loss of biological activity. The gene fragment encoding blad has been sequenced, cloned and expressed with full biological activity in the bacterium Escherichia coli.

Blad is therefore a multifunctional polypeptide exhibiting a wide array of unique properties: 1) It is edible to man and higher animals; 2) It is nontoxic to the environment; 3) It exhibits a potent antifungal activity towards all fungal species tested so far (>40); 4) It has both preventive and curative fungicide activities; 5) It displays strong plant growth promoter activity; 6) Its fungicide and plant stimulant activities are greater or equal to those displayed by the best commercial products available; 7) Its mode of action makes it unlikely for the target fungi to develop resistance mechanisms.

Blad will soon become commercially available as a plant analeptic and within approximately one year as a fungicide, both manufactured by CEV-Biotecnologia das Plantas, S.A.