Comprehensive transcriptome analysis of different potato cultivars provides insight into early blight disease caused by Alternaria solani

Abstract

Background Early blight, caused by the necrotrophic fungal pathogen Alternaria solani, is an economically important disease affecting the tuber yield worldwide. The disease is mainly controlled by chemical plant protection agents. However, over-using these chemicals can lead to the evolution of resistant A. solani strains and is environmentally hazardous. Identifying genetic disease resistance factors is crucial for the sustainable management of early blight but little effort has been diverted in this direction. Therefore, we carried out transcriptome sequencing of the A. solani interaction with different potato cultivars with varying levels of early blight resistance to identify key host genes and pathways in a cultivar-specific manner. Results In this study, we have captured transcriptomes from three different potato cultivars with varying susceptibility to A. solani, namely Magnum Bonum, Désirée, and Kuras, at 18 and 36 h post-infection. We identified many differentially expressed genes (DEGs) between these cultivars, and the number of DEGs increased with susceptibility and infection time. There were 649 transcripts commonly expressed between the potato cultivars and time points, of which 627 and 22 were up- and down-regulated, respectively. Interestingly, overall the up-regulated DEGs were twice in number as compared to down-regulated ones in all the potato cultivars and time points, except Kuras at 36 h post-inoculation. In general, transcription factor families WRKY, ERF, bHLH, MYB, and C2H2 were highly enriched DEGs, of which a significant number were up-regulated. The majority of the key transcripts involved in the jasmonic acid and ethylene biosynthesis pathways were highly up-regulated. Many transcripts involved in the mevalonate (MVA) pathway, isoprenyl-PP, and terpene biosynthesis were also up-regulated across the potato cultivars and time points. Compared to Magnum Bonum and Désirée, multiple components of the photosynthesis machinery, starch biosynthesis and degradation pathway were down-regulated in the most susceptible potato cultivar, Kuras. Conclusions Transcriptome sequencing identified many differentially expressed genes and pathways, thereby contributing to the improved understanding of the interaction between the potato host and A. solani. The transcription factors identified are attractive targets for genetic modification to improve potato resistance against early blight. The results provide important insights into the molecular events at the early stages of disease development, help to shorten the knowledge gap, and support potato breeding programs for improved early blight disease resistance.

Including Measurement Effects and Temporal Variations in VIS-NIRS Models to Improve Early Detection of Plant Disease: Application to Alternaria Solani in Potatoes

“…In that context, it could be considered to study the effects of plant age, leaf position, metabolic content before infection or even compounds inducing plant resistance. A recent transcriptomic study (Sajeevan et al, 2023) captured major transcription factor families whose differential expressed genes are associated with resistance or susceptibility to early blight within potato cultivars. Associating these findings with hyperspectral imaging could improve the robustness of statistical models aiming at predicting health status and infection stages.…”

“…Here, we investigated the interactions of A. solani with seven potato cultivars at early time points after inoculation. These cultivars have varying degree of susceptibility, and we know different types of transcriptome response to A. solani (Sajeevan et al, 2023).…”

Alternaria diseases on potato and tomato

“…Plant immune systems mirror this bipolar spectrum of bio-and necrotrophic nutrition in the mutual antagonism of the two major defence hormones salicylic acid (SA) and jasmonic acid (JA) (Thaler et al, 2012). SA and JA regulate defence responses to bio-and necrotrophs, respectively (Robert-Seilaniantz EBDC pathogenesis seems to be somewhat controversial (Brouwer et al, 2021;Sajeevan et al, 2023), JA seems to be a major transcriptional regulator of EBDC defence responses (Zheng et al, 2022).…”

“…Ethylene (ET) plays a significant role in necrotroph defence as ET signalling abolishes SA/JA antagonism (Leon‐Reyes et al., 2010 ), yielding priority to JA signalling pathways. Hormone signalling induces vigorous transcriptional responses, and although the specific role of JA in EBDC pathogenesis seems to be somewhat controversial (Brouwer et al., 2021 ; Sajeevan et al., 2023 ), JA seems to be a major transcriptional regulator of EBDC defence responses (Zheng et al., 2022 ).…”

Transcriptome analysis of genes involved in the pathogenesis mechanism of potato virus Y in potato cultivar YouJin

“…In recent years, potato ( Solanum tuberosum L.) has played an important role as a food crop in ensuring food security at the national level ( Sajeevan et al, 2023 ). Increased consumption of potato in Asian countries such as China and India is the main driver of its overall consumption growth ( Shahbandeh, 2023 ).…”