Biology subjects

Gueco, L. S.

Publications and source records attributed to Gueco, L. S..

3 recordsLinked to original sources

bioRxiv2023

Development and validation of allele specific RLK gene markers for banana bunchy top disease (BBTD) resistance in banana

As global demand for bananas rises, the threat of banana bunchy top disease (BBTD), caused by banana bunchy top virus (BBTV), poses a significant constraint to sustainable banana production. To circumvent this, it is critical to fast-track the development of BBTV-resistant banana cultivars. In a dataset of differentially expressed genes between BBTV-resistant and susceptible bananas, six RLK genes involved in plant defense against pathogens were exclusively upregulated in the BBTV-resistant wild Musa balbisiana compared to the BBTV-susceptible Musa acuminata cv. Lakatan. Here, two genic variants of RLKs, single nucleotide polymorphisms (SNPs) and simple sequence repeats (SSR), were identified in 10 banana accessions representing major genomic groupings. Nine gene-specific markers were developed using three marker systems: SSR, allele-specific PCR, and tetra primer amplification refractory mutation system PCR markers. Six of these were polymorphic and successfully discriminated 117 Musa genotypes at the NPGRL-IPB ex situ germplasm, with an average polymorphism information content of 0.36 for SNP markers and 0.49 for SSR marker, both of which are moderately informative. These markers facilitated the construction of a dendrogram using the Unweighted Neighbor-Joining (UNJ) method with 1000 bootstrap iterations, identifying four major clades: M. acuminata spp. and other Musa spp. (I), wild M. balbisiana (BBw) and other accessions with high-proportion of B-genome (II & III), hybrid bananas (triploids and tetraploids) (IV), which revealed the genetic diversity and relationships among Musa accessions. Ultimately, this genomic resource will aid in positioning the Philippines as a key player in banana disease resistance breeding towards a food-secure banana industry.

genetics↗

bioRxiv2022

Comparative RNA-seq analysis of resistant and susceptible banana genotypes reveals molecular mechanisms in response to Banana bunchy top virus (BBTV)

Banana is a major fruit crop in the Philippines and remains to be a large contributor to the countrys dollar reserve. Among the main hindrances in global banana production, diseases such as Banana bunchy top disease (BBTD) caused by BBTV can bring catastrophic loss to any banana plantation. To elucidate the resistance mechanism and understand the interplay of host factors in the presence of the invading pathogen, we implemented RNA-seq-based comparative transcriptomics analyses of mock- and BBTV-inoculated resistant (wild M. balbisiana) and susceptible (M. acuminata Lakatan) banana genotypes. Similar patterns of expression for 119 differentially expressed genes (DEGs) were observed on both genotypes, representing the typical defense response of banana to BBTV. A set of 173 DEGs specific to the susceptible Lakatan banana cultivar revealed potential host factors and susceptibility mechanisms involved in successful BBTV infection. Further, differential transcriptomic analysis revealed 268 DEGs exclusive to the resistant wild M. balbisiana, unraveling insights into the complex resistance mechanisms involved in BBTV defense such as pathogen perception, phytohormone action, reactive oxygen species (ROS), hypersensitive response (HR), production of secondary metabolites and cell wall modification. The DEGs identified in this study will aid in the design of foreground markers for the precise integration of resistance genes during marker-assisted breeding programs. Furthermore, the application of these results will also enable the foreseen deployment of genome-edited banana cultivars targeting the resistance and host factor genes towards a future-proof banana industry.

genomics↗

bioRxiv2022

Resistance of Musa balbisiana accessions of the Philippines to banana bunchy top virus

Mitigation of banana bunchy top disease (BBTD) is still a challenge worldwide. BBTD is caused by banana bunchy top virus (BBTV), the most important virus affecting banana. Currently, no cultivar or accession of banana has complete resistance to BBTD. A total of 36 wild Musa spp. accessions, including 34 Musabalbisiana and two M. acuminata subsp. errans ( Agutay), were screened for resistance against BBTV. In greenhouse tests using viruliferous banana aphids (Pentalonia nigronervosa), all M. balbisiana accessions remained symptomless and BBTV was not detected in any of these plants by PCR at three- and six-months post inoculation. In contrast, 100% disease incidence was recorded in M. acuminata subsp. errans and in cv. Lakatan susceptible control plants. The PCR-negative M.balbisiana plants were then transferred to a field with high BBTV inoculum pressure where they remained symptomless and PCR-negative for up to five years, while all cv. Lakatan developed BBTD. This study confirmed the resistance of wild M.balbisiana accessions to BBTV. It is therefore expected to provide a resource for conventional and marker assisted breeding.

pathology↗