Abstract
Sweet potato virus disease (SPVD) is the most devastating viral disease in sweet potato (Ipomoea batatas (L.) Lam.), causing substantial yield losses worldwide. We conducted a systemic investigation on the spread, transmission, and pathogenesis of SPVD. Field experiments conducted over two years on ten sweet potato varieties showed that SPVD symptoms first occurred in newly developed top leaves, and spread from adjacent to distant plants in the field. The SPVD incidence was mainly (but not only) determined by the resistance of the varieties planted, and each variety exhibited a characteristic subset of SPVD symptoms. SPVD was not robustly transmitted through friction inoculation, but friction of the main stem might contribute to a higher SPVD incidence rate compared to friction of the leaf and branch tissues. Furthermore, our results suggested that SPVD might be latent in the storage root. Therefore, using virus-free storage roots and cuttings, purposeful monitoring for SPVD according to variety-specific symptoms, and swiftly removing infected plants (especially during the later growth stages) would help control and prevent SPVD during sweet potato production. Comparative transcriptome analysis revealed that numerous genes involved in photosynthesis, starch and sucrose metabolism, flavonoid biosynthesis, and carotenoid biosynthesis were downregulated following SPVD, whereas those involved in monolignol biosynthesis, zeatin biosynthesis, trehalose metabolism, and linoleic acid metabolism were upregulated. Notably, critical genes involved in pathogenesis and plant defense were significantly induced or suppressed following SPVD. These data provide insights into the molecular changes of sweet potato in response to SPVD and elucidate potential SPVD pathogenesis and defense mechanisms in sweet potato. Our study provides important information that can be used to tailor sustainable SPVD control strategies and guide the molecular breeding of SPVD-resistant sweet potato varieties.
Highlights
Sweet potato is an important and versatile crop that is widely grown throughout the world as an edible tuber, a green vegetable, a nutritional supplement, a livestock feed, an ornamental plant, Plants 2020, 9, 492; doi:10.3390/plants9040492 www.mdpi.com/journal/plantsPlants 2020, 9, 492 an industrial raw material, and a potential bioethanol feedstock [1,2]
Natural sweet potato virus disease (SPVD) transmission did occur between plants of the other varieties, and the incidence rate increased over the course of the growth season
Our survey of the distribution and spread of SPVD in 10 sweet potato varieties revealed several features of SPVD spread in the field, meaning some SPVD control strategies can be tailored
Summary
Sweet potato is an important and versatile crop that is widely grown throughout the world as an edible tuber, a green vegetable, a nutritional supplement, a livestock feed, an ornamental plant, Plants 2020, 9, 492; doi:10.3390/plants9040492 www.mdpi.com/journal/plantsPlants 2020, 9, 492 an industrial raw material, and a potential bioethanol feedstock [1,2]. Sweet potato is an important and versatile crop that is widely grown throughout the world as an edible tuber, a green vegetable, a nutritional supplement, a livestock feed, an ornamental plant, Plants 2020, 9, 492; doi:10.3390/plants9040492 www.mdpi.com/journal/plants. Sweet potato’s high yield potential and adaptability to a wide range of environmental conditions make it an important staple and food security crop in many regions of the world, especially in developing countries [3]. The most devastating disease in sweet potato globally is sweet potato virus disease (SPVD), which is caused by co-infection by aphid-borne sweet potato feathery mottle virus (SPFMV) and whitefly-borne sweet potato chlorotic stunt virus (SPCSV) [4]. A series of control measures have been developed to prevent SPVD in sweet potato production 90% and poses a significant constraint on sweet potato production [5,6].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
