Natural biodiversity is an important source for humans since ancient times. However, biodiversity is experiencing a dramatic decline and many species are at extinction risk. Climate change and human activity are the main drivers of non-sustainable landscape conservation and management. The opportunity to dampen climate change effects is provided by indigenous species, domesticated in local contexts but are little investigated. In this framework, this PhD thesis aims at developing strategies to valorise natural biodiversity, considering different integrative scientific aspects. The first objective of this thesis is the rediscovery of a traditional African legume, Vigna unguiculata (L.) Walp., and assess its adaptability to stressful conditions typically caused by climate change or undemanding agricultural practices. Moreover, the research for bioactive compounds is an added value to give consciousness of the species potential. For this purpose, exploration of genetic diversity of known legume bioactive compounds, the Bowman-Birk protease inhibitors (BBIs) and appraisal of their nutraceutical properties are the second objectives of the project. A multidisciplinary experimental overview has been applied by integrating different approaches to create a coherent workflow. The demonstration of Vigna unguiculata L. as suitable species for climate change was carried out with a field experiment and subsequent laboratory analyses to evaluate production parameters and metabolic features. The genetic diversity of this species was explored through molecular biology techniques and in silico computational and phylogenetic analyses. The nutraceutical features were established by biochemical procedures and cellular biology by testing compounds on different ageing and cancer models. From the point of view of cultivation needs, it is possible to consider V. unguiculata (L.) Walp. as undemanding in terms of water demand and agronomic practices. This makes this legume suitable for conservation agriculture practices in developing countries and where climate change is having a dramatic impact on indigenous crop. This legume is also an important resource of essential macronutrients and to enhance this species and promote its cultivation globally, we also wanted to focus on the presence of bioactive molecules with direct action on humans. The genetic exploration considered almost 200 accessions and found 13 isoforms of BBI were identified in different wild and cultivated accessions, distributed in the African continent and in other areas of the world. Furthermore, we managed to develop an extraction and purification procedure to isolate single isoforms and characterise them. Our data suggest that V. unguiculata BBIs possess a great natural genetic and biochemical diversity. Moreover, the demonstration of BBI-related bioactivities on different models makes them very promising as a high-value natural compound for human wellbeing. The direct action on different tumour cell lines suggests a possible therapeutic application also in synergy with some drugs (i.e. Cetuximab). This opens opportunities for future research on similar related species and genera, and on the analyses to evaluate the most effective isoforms also in in vivo systems. In conclusion, this PhD project demonstrates that i) bioprospection of local species directed to the search for bioactive molecules represents an important lever for safeguarding; ii) the knowledge of evolution and diversification of the plants of interest is a tool to improve bioprospecting actions and identify molecular variants of bioactive compounds; iii) analyses of functional efficacy of bioactive compounds in in vitro and in vivo systems is a fundamental step to dedicate scientific research to the enhancement of biodiversity in an operational context. This is an essential phase to stimulate private investors and businesses to bring economic and social value and biodiversity conservation.

La biodiversità naturale è un’importante risorsa per l’uomo sin da tempi antichi. Tuttavia, sta sperimentando un critico declino e molte specie sono a rischio estinzione. Il cambiamento climatico e l’attività umana sono i maggiori drivers di una conservazione e gestione del territorio non sostenibili. L’opportunità di ammortizzare gli effetti del cambiamento climatico è fornita da specie indigene, domesticate in contesti locali ma poco investigate. In questo contesto, questa tesi mira a sviluppare strategie per valorizzare la biodiversità naturale, considerando diversi e integrati aspetti scientifici. Il primo obiettivo è quello di riscoprire un legume tradizionale africano, Vigna unguiculata (L.) Walp., e verificare la sua adattabilità a condizioni di stress tipiche del cambiamento climatico o pratiche agricole poco esigenti. La ricerca di composti bioattivi è un valore aggiunto al fine di dare coscienza della potenzialità della specie. Per questa ragione, i successivi obiettivi della tesi sono l’esplorazione della diversità genetica di composti bioattivi dei legumi, gli inibitori delle proteasi Bowman-Birk (BBIs), e la valutazione delle proprietà nutraceutiche. Un design sperimentale multidisciplinare è stato applicato integrando diversi approcci per creare un flusso di lavoro coerente. Un esperimento di campo e analisi di produzione e metaboliti è stato organizzato per dimostrare l’adeguatezza di Vigna unguiculata come coltivazione per il cambiamento climatico. La diversità genetica di questa specie è stata esplorato con tecniche di biologia molecolare e analisi computazionali e filogenetiche. Le proprietà nutraceutiche sono state determinate grazie a procedure biochimiche e test su modelli, cellulari e in vivo, di cancro ed invecchiamento. Dal punto di vista della coltivazione, Vigna unguiculata può essere considerata una specie poco esigente in termini di richiesta d’acqua e pratiche agronomiche. Ciò rende questo legume adatto a pratiche di agricoltura conservativa in paesi in via di sviluppo o in quei paesi colpiti fortemente dal cambiamento climatico. Questo legume si dimostra importante come risorsa di macronutrienti essenziali, e, per promuovere la sua diffusione a livello globale, abbiamo indagato anche la presenza di molecole con azione dirette per la salute umana. L’esplorazione genetica ha considerato quasi 200 accessioni, tovando13 diverse isoforme di BBI tra accessioni selvatiche e domesticate distribuite sul continente Africa e in altre parti del mondo. In aggiunta, abbiamo sviluppato una metodica estrattiva e purificative che ha permesso l’isolamento e caratterizzazione delle singole isoforme di BBI. La dimostrazione di attività correlate a BBI nei diversi modelli, rende questa famiglia di proteine un valore aggiunto per la salute umana. L’azione verso linee cellulari tumorali suggerisce possibili applicazioni terapeutiche anche in sinergia con farmaci d’elezione. Ciò apre opportunità per la futura ricerca in specie e generi affini e la valutazione di isoforme maggiormente efficaci anche in sistemi in vivo. Concludendo, questo progetto dimostra che i) la bioprospezione per la ricerca di molecole bioattive in specie regionali è un importante passo per la loro salvaguardia, ii) conoscere evoluzione e diversificazione di piante di interesse è uno strumento per migliorare azioni bioprospettive e identificare migliori varianti di composti bioattivi, iii) analisi di efficacia funzionale in vitro e in vivo è un passaggio fondamentale per dedicare ricerca scientifica al miglioramento della biodiversità in contesti operativi. Quest’ultima è una fase importante per stimolare investitori, sia privati che pubblici, al fine di portare valore economico e sociale alla conservazione della biodiversità.

(2023). A Bioprospecting Multidisciplinary Approach to Valorise Biodiversity: The Case of Bowman-Birk Protease Inhibitors in Vigna unguiculata (L.) Walp.. (Tesi di dottorato, Università degli Studi di Milano-Bicocca, 2023).

A Bioprospecting Multidisciplinary Approach to Valorise Biodiversity: The Case of Bowman-Birk Protease Inhibitors in Vigna unguiculata (L.) Walp.

PANZERI, DAVIDE
2023

Abstract

Natural biodiversity is an important source for humans since ancient times. However, biodiversity is experiencing a dramatic decline and many species are at extinction risk. Climate change and human activity are the main drivers of non-sustainable landscape conservation and management. The opportunity to dampen climate change effects is provided by indigenous species, domesticated in local contexts but are little investigated. In this framework, this PhD thesis aims at developing strategies to valorise natural biodiversity, considering different integrative scientific aspects. The first objective of this thesis is the rediscovery of a traditional African legume, Vigna unguiculata (L.) Walp., and assess its adaptability to stressful conditions typically caused by climate change or undemanding agricultural practices. Moreover, the research for bioactive compounds is an added value to give consciousness of the species potential. For this purpose, exploration of genetic diversity of known legume bioactive compounds, the Bowman-Birk protease inhibitors (BBIs) and appraisal of their nutraceutical properties are the second objectives of the project. A multidisciplinary experimental overview has been applied by integrating different approaches to create a coherent workflow. The demonstration of Vigna unguiculata L. as suitable species for climate change was carried out with a field experiment and subsequent laboratory analyses to evaluate production parameters and metabolic features. The genetic diversity of this species was explored through molecular biology techniques and in silico computational and phylogenetic analyses. The nutraceutical features were established by biochemical procedures and cellular biology by testing compounds on different ageing and cancer models. From the point of view of cultivation needs, it is possible to consider V. unguiculata (L.) Walp. as undemanding in terms of water demand and agronomic practices. This makes this legume suitable for conservation agriculture practices in developing countries and where climate change is having a dramatic impact on indigenous crop. This legume is also an important resource of essential macronutrients and to enhance this species and promote its cultivation globally, we also wanted to focus on the presence of bioactive molecules with direct action on humans. The genetic exploration considered almost 200 accessions and found 13 isoforms of BBI were identified in different wild and cultivated accessions, distributed in the African continent and in other areas of the world. Furthermore, we managed to develop an extraction and purification procedure to isolate single isoforms and characterise them. Our data suggest that V. unguiculata BBIs possess a great natural genetic and biochemical diversity. Moreover, the demonstration of BBI-related bioactivities on different models makes them very promising as a high-value natural compound for human wellbeing. The direct action on different tumour cell lines suggests a possible therapeutic application also in synergy with some drugs (i.e. Cetuximab). This opens opportunities for future research on similar related species and genera, and on the analyses to evaluate the most effective isoforms also in in vivo systems. In conclusion, this PhD project demonstrates that i) bioprospection of local species directed to the search for bioactive molecules represents an important lever for safeguarding; ii) the knowledge of evolution and diversification of the plants of interest is a tool to improve bioprospecting actions and identify molecular variants of bioactive compounds; iii) analyses of functional efficacy of bioactive compounds in in vitro and in vivo systems is a fundamental step to dedicate scientific research to the enhancement of biodiversity in an operational context. This is an essential phase to stimulate private investors and businesses to bring economic and social value and biodiversity conservation.
LABRA, MASSIMO
Biodiversità; Cambiamento Clima; Vigna unguiculata; Bowman-Birk; Composti Bioattivi
Biodiversity; Climate Change; Vigna unguiculata; Bowman-Birk; Bioactive Compounds
BIO/01 - BOTANICA GENERALE
Italian
24-feb-2023
TECNOLOGIE CONVERGENTI PER I SISTEMI BIOMOLECOLARI (TeCSBi)
35
2021/2022
open
(2023). A Bioprospecting Multidisciplinary Approach to Valorise Biodiversity: The Case of Bowman-Birk Protease Inhibitors in Vigna unguiculata (L.) Walp.. (Tesi di dottorato, Università degli Studi di Milano-Bicocca, 2023).
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Descrizione: A Bioprospecting Multidisciplinary Approach to Valorise Biodiversity: The Case of Bowman-Birk Protease Inhibitors in Vigna unguiculata (L.) Walp.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/404605
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