ABSTRACT
Agricultural crops are exposed to various abiotic stresses, such as salinity, water deficits, temperature extremes, floods, radiation, and metal toxicity. To overcome these challenges, breeding programs seek to improve methods and techniques. Gene editing by Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR/Cas-is a versatile tool for editing in all layers of the central dogma with focus on the development of cultivars of plants resistant or tolerant to multiple biotic or abiotic stresses. This systematic review (SR) brings new contributions to the study of the use of CRISPR/Cas in gene editing for tolerance to abiotic stress in plants. Articles deposited in different electronic databases, using a search string and predefined inclusion and exclusion criteria, were evaluated. This SR demonstrates that the CRISPR/Cas system has been applied to several plant species to promote tolerance to the main abiotic stresses. Among the most studied crops are rice and Arabidopsis thaliana, an important staple food for the population, and a model plant in genetics/biotechnology, respectively, and more recently tomato, whose number of studies has increased since 2021. Most studies were conducted in Asia, specifically in China. The Cas9 enzyme is used in most articles, and only Cas12a is used as an additional gene editing tool in plants. Ribonucleoproteins (RNPs) have emerged as a DNA-free strategy for genome editing without exogenous DNA. This SR also identifies several genes edited by CRISPR/Cas, and it also shows that plant responses to stress factors are mediated by many complex-signaling pathways. In addition, the quality of the articles included in this SR was validated by a risk of bias analysis. The information gathered in this SR helps to understand the current state of CRISPR/Cas in the editing of genes and noncoding sequences, which plays a key role in the regulation of various biological processes and the tolerance to multiple abiotic stresses, with potential for use in plant genetic improvement programs.
ABSTRACT
The fungus Fusarium oxysporum f. sp. cubense (FOC), tropical race 4 (TR4), causes Fusarium wilt of banana, a pandemic that has threatened the cultivation and export trade of this fruit. This article presents the first systematic review of studies conducted in the last 10 years on the resistance of Musa spp. to Fusarium wilt. We evaluated articles deposited in different academic databases, using a standardized search string and predefined inclusion and exclusion criteria. We note that the information on the sequencing of the Musa sp. genome is certainly a source for obtaining resistant cultivars, mainly by evaluating the banana transcriptome data after infection with FOC. We also showed that there are sources of resistance to FOC race 1 (R1) and FOC TR4 in banana germplasms and that these data are the basis for obtaining resistant cultivars, although the published data are still scarce. In contrast, the transgenics approach has been adopted frequently. We propose harmonizing methods and protocols to facilitate the comparison of information obtained in different research centers and efforts based on global cooperation to cope with the disease. Thus, we offer here a contribution that may facilitate and direct research towards the production of banana resistant to FOC.
ABSTRACT
O objetivo deste trabalho foi determinar a concentração de polifenóis totais, flavonóides, vitamina C e carotenóides totais em 61 acessos de banana pertencentes ao Banco Ativo de Germoplasma de bananeira da Embrapa Mandioca e Fruticultura. Foram detectadas diferenças significativas para todas as características analisadas por meio da análise de variância. A média para os teores de polifenóis totais entre os 61 acessos de banana foi de 38,06mg 100g-1, com variação de 12,51mg 100g-1 para o triplóide 'Torp' a 257,80mg 100g-1 para o tetraplóide 'Teparod'. A média para flavonóides foi de 2,09mg 100g-1, variando de 0,85mg 100g-1 ('Maravilha' AAAB) a 6,63mg 100g-1 ('Teparod' ABBB). Para vitamina C, a média foi de 21,60mg 100g-1, variando de 8,60mg 100g-1 (tetraplóide 'Bucaneiro') a 76,82mg 100g-1 (tetraplóide 'Teparod'). A média do teor de carotenóides totais foi de 4,34mg g-1, variando de 1,18mg g-1 ('Champa Madras', triplóide ABB) a 19,24mg g-1 ('Saney', triplóide AAB). Os diplóides Modok Gier e NBA-14 apresentaram, respectivamente, quatro e cinco vezes mais carotenóides totais que as cultivares do grupo Cavendish ('Nanica', 'Willians' e 'Lacatan'). Esses resultados permitem concluir sobre a possibilidade da obtenção de cultivares com altos níveis de compostos funcionais por meio de cruzamentos e seleção. Cultivares com este perfil têm potencial como alimento funcional, ajudando a prevenir doenças, por meio da neutralização de radicais livres.
The objective of this research was to determine the concentration of polyphenols, flavonols, vitamin C and carotenoid and in 61 banana accessions from Musa germplasm collection from Embrapa Cassava and Fruits, Brazil. Was detected significant differences for all characteristic analyzed in ANOVA. The average for polyphenols among the 61 accessions was of 38.06mg 100g-1, with variation of 12.51mg 100g-1 for the triploid 'Torp' to 257.80mg 100g-1 for the tetraploid 'Teparod'. The average for flavonols was of 2.09mg 100g-1, ranging of 0.85mg 100g-1 ('Maravilha' AAAB) to 6.63mg 100g-1 ('Teparod' ABBB). The average for vitamin C was of 21.60mg 100g-1, ranging of 8.60mg 100g-1 (tetraploid 'Bucaneiro') to 76.82mg 100g-1 (tetraploid 'Teparod'). The average of the total carotenoids was of 4.34g g-1, ranging of 1.18g g-1 ('Champa Madras', triploid ABB) to 19.24g g-1 ('Saney', triploid AAB). Diploids Modok Gier and NBA-14 exhibited 4- and 5-fold increased carotenoid content in comparison to the representatives from the Cavendish group ('Nanica', 'Willians' and 'Lacatan'). These results allow ending about the possibility of the obtaining new cultivars with high levels of functional compositions through crossings and selection. Cultivar with this profile has potential of neutralizing free radicals and to prevent diseases.
