PubMed HealthSearch

Biomedical subjects

Pingfei Ge

Publications and source records attributed to Pingfei Ge.

2 recordsLinked to original sources

The TANG cluster comprising ten nitrate transporter genes controls fruit sweetness and size in tomato.

Sucrose is a major transport form of photoassimilated carbon in tomato, Arabidopsis, and many other plant species, and plays a critical regulatory role in plant growth, development, and fruit quality. Plant vacuoles function as storage organelles, accumulating substantial quantities of metabolically inactive nitrates as a nitrogen reserve and soluble sugars as a carbon reserve. Consequently, the balance between nitrate and sucrose accumulation determines plant growth dynamics and fruit taste. In this study, we identified a gene cluster designated TANG (Total soluble solidsAccumulation viaNitrate transporterGene cluster), comprising ten nitrate transporter genes that are significantly associated with sucrose accumulation in tomato. This gene cluster mediates the transport of nitrate between the cytoplasm and vacuole, thereby influencing its storage. Functional disruption of TANG8, a member of the gene cluster, results in either enhanced sugar accumulation or increased fruit size. Selective disruption of multiple TANG cluster members yields fruits with elevated sweetness and increased fruit size in S. pimpinellifolium. The interaction between the TANG members and a tonoplast localized Sucrose Transporter 4 provides insight into the competitive accumulation of nitrate and sugar. The multiplex editing of a gene cluster provides a successful example of engineering crops with high quality and yield.

Gene cluster

Ethylene response factors ERF.B2 and ERF.B5 synergically regulate ascorbic acid biosynthesis at multiple sites in tomato.

Ascorbic acid (AsA) is an important growth regulator and antioxidant in plants. It is acknowledged as a quality indicator in tomato (Solanum lycopersicum). Although the AsA biosynthetic pathway has been elucidated, its regulatory mechanisms remain largely unknown. In the present study, two members of the ethylene response factor (ERF) family, SlERF.B2 and SlERF.B5, were found to be co-expressed with SlGGP1, a pivotal gene in AsA biosynthesis. These two transcription factors were biochemically confirmed to bind to the DRE motif (GCCGAC/GTCGGC) of the SlGGP1 promoter. Notably, the SlERF.B2 and SlERF.B5 functioned as a dimer to regulate SlGGP1 expression and AsA biosynthesis. Overexpression of SlERF.B2 and SlERF.B5 enhanced the AsA levels up to 149 and 140%, respectively, whereas knockout of either of them could significantly decrease the AsA levels by up to 27%. DNA affinity purification sequencing (DAP-seq) indicated that SlERF.B2 synergistically regulates AsA biosynthesis at multiple sites by targeting the promoters of SlGPI and SlDHAR1. Overexpression of SlERF.B2 or SlERF.B5 in tomato conferred a high capacity for scavenging reactive oxygen species and enhanced tolerance to oxidation and salt stress, potentially by elevating the AsA content. This study unravels novel regulators of AsA biosynthesis and elucidates a molecular network that should facilitate the improvement of this nutrient in tomato and enhance stress tolerance in plants.

Solanum lycopersicum