SlMYB1regulates the accumulation of lycopene, fruit shape, and resistance toBotrytis cinereain tomato

Abstract

Fruit lycopene, shape, and resistance are essential traits in vegetables whose final product is fruit, and they are also closely related to and strictly regulated by multiple transcription factors. Lycopene, which can not be synthesized by human body only can ingested from the outside, was important in maintaining human health. During fruit ripening and post-harvest, tomato plants face a variety of biotic or abiotic stresses, which might inflict great damage to fruit quality due to its flat shape and pointed tip during storage and transportation. Therefore, there is an urgent need for key molecular switches to simultaneously improve fruit lycopene and resistance to biotic stress during ripening. Here, we identified the MYB transcription factor SlMYB1 in tomato plants which could bind to the promoters of lycopene synthesis-related genes, SlLCY1, SlPSY2, and the pathogen-related gene SlPR5 directly, to regulate the fruit lycopene and resistance to Botrytis cinerea in tomato. In addition to regulating lycopene synthesis, SlMYB1 also regulates the content of soluble sugar, soluble protein and flavonoid in tomato. What’s more, SlMYB1 could regulate the tomato fruit shape, making it smoother or flatter to prevent skin damage caused by vibration on fruits. RNA sequencing (RNA-seq) further showed that SlMYB1 fruit-specific expression lines had multiple differentially expressed genes compared with those from wild-type plants, suggesting that SlMYB1 might have multiple roles in fruit nutritional quality control and resistance to stresses, which is a rare occurrence in previous studies. In summary, our results revealed that SlMYB1 was an essential multi-functional transcription factor that could regulate the lycopene and resistance to Botrytis cinerea, and change the shape of fruit in tomato plants.

Functional Analysis of SmMYB39 in Salt Stress Tolerance of Eggplant (Solanum melongena L.)

“…MYB transcription factors play important roles in the response of Solanaceae plants to biotic and abiotic stresses. Research findings have indicated that the fruit-specific expression of SlMYB1 improved the tomato fruit quality and resistance to B. cinerea [27]. The impact of ectopic expression of MdoMYB121 under salt stress on tomato seedlings was investigated by researchers.…”

Cloning, Expression, and Functional Analysis of the MYB Transcription Factor SlMYB86-like in Tomato

“…Liu et al [ 43 ] knocked out the SlMYBS2 gene in the tomato using CRISPR/Cas9 technology, and the number of necrotic cells, the severity of lesions, and the disease index were higher, and the resistance to Phytophthora infestation was lower in transgenic plants than in wild-type plants. Yin et al [ 44 ] showed that SlMYB1 is an important multifunctional TF that can regulate the resistance of the tomato to Botrytis cinerea . Shan et al [ 26 ] showed that overexpression of TaMYB86 significantly enhances resistance to B. sorokiniana in transgenic wheat lines and that TaMYB86 plays a positive role in the defense response to B. sorokiniana .…”

Recent Advances in Mechanisms Underlying Defense Responses of Horticultural Crops to Botrytis cinerea

“…Tomato SlMYB75 increased the accumulation of JA and activated the JA defense signaling pathway upon B. cinerea infection [62]. Tomato SlMYB1 binds to the promoters of lycopene synthesis-related genes (SlLCY1 and SlPSY2) and the pathogen-related gene SlPR5 to regulate lycopene production and plant resistance to B. cinerea [63]. VvMYB44 directly activated the transcripts of enzyme-encoding genes involved in phenylpropanoid and sucrose metabolism [64].…”