Potato late blight caused by Phytophthora infestans threatens global food security. Unlike the fact that most race-specific resistance to P. infestans (Rpi) genes is rapidly overcome by evolving pathogen populations, the R8 gene from Solanum demissum has conferred durable, quantitative resistance for nearly a century despite encoding a canonical coiled-coil–type nucleotide-binding, leucine-rich repeat (NLR) protein. We identified specific R8 gene analogs that act as negative modulators of R8-mediated immunity. These R8 gene analogs lack independent resistance functions but perturb the recognition of avirulence effector Avr8 by R8 and interfere with oligomerization and plasma membrane association of NRC2, a helper NLR essential for the R8 signaling pathway. Stable overexpression of such RGAs effectively compromises R8-mediated resistance in both potato and Nicotiana benthamiana. We propose that this endogenous regulation balances the intensity of R8-mediated immunity, likely reducing selection pressure on the pathogen population and prolonging resistance durability. Our findings reveal a regulatory layer where genetically linked RGAs control resistance (R) protein–mediated immunity, providing a conceptual framework for durable resistance breeding.
Jia-Hui Nie, Lang Liu, Ye-Tong Qi et al.· Science Advances· 0 citations
Differential coloration of potato tuber skin is an important agronomic trait. However, its genetic regulatory mechanism remains unclear. In this study, an F₁ segregation population was constructed, and segregation in tuber skin coloration was observed. Using bulked segregant analysis by sequencing (BSA-seq) combined with fine mapping, a major quantitative trait locus (QTL) was mapped to a 52.24–53.08 Mb interval on Chr10. Within this region, StMYBA1, an R2R3-MYB transcription factor, emerged as the key candidate gene. Notably, a 6-bp (CTCCTC) deletion in the exon of StMYBA1 caused the loss of two proline residues, which was strongly associated with the absence of differential skin coloration. Further investigations demonstrated that overexpression of StMYBA1 markedly enhanced anthocyanin accumulation in both leaves and tubers. In transgenic lines, delphinidin content in leaves increased by 216.6%–297.4%, and after five days of light exposure, tuber eyes and heels exhibited a pronounced purple pigmentation. Consistently, key anthocyanin biosynthetic genes, including StANS and StF3′H, were significantly upregulated. Dual-luciferase assays further confirmed that StMYBA1 promotes anthocyanin biosynthesis by activating the MYB transcription factor StAN2 and its downstream targets. Importantly, the 6-bp deletion partially attenuated StMYBA1 regulatory activity, as reflected by reduced activation of several anthocyanin-related promoters and moderately lower anthocyanin accumulation in transient assays, while DNA-binding activity was retained. Collectively, these findings provide new insights into the regulatory role of StMYBA1 in potato anthocyanin biosynthesis and identify a potentially useful genetic target for potato quality improvement.
Xi-Juan Zhao, Chen-Xi Li, Sheng-Xuan Liu et al.· Horticulture Research· 0 citations
Apical dominance is a key determinant of plant architecture and yield formation in crops. Auxin and jasmonic acid are crucial endogenous regulators of this process, yet their functions in the above‐ground shoots and underground modified stems (tubers) of asexually propagated potato plants remain largely unclear. Here, we demonstrate that the jasmonate pathway component
StJAZ1‐like
promotes the release of apical dominance in potato.
StJAZ1‐like
overexpression enhanced axillary bud outgrowth, increased shoot branching and triggered multi‐bud sprouting from individual tuber eyes. Transcriptome profiling of dormant axillary buds revealed pronounced alterations in hormone‐related pathways, including marked upregulation of the auxin efflux carrier
StPIN3
, accompanied by reduced indole‐3‐acetic acid (IAA) and abscisic acid (ABA) levels in axillary buds. Consistently, functional analyses demonstrated that
StPIN3
positively regulates lateral branching and tuber sprouting, indicating that
StPIN3
acts downstream of StJAZ1‐like. Mechanistically, StJAZ1‐like physically interacts with StPIF02, a bHLH transcription factor. StPIF02 directly binds the
StPIN3
promoter and activates its transcription. Collectively, our results suggest a StJAZ1‐like–StPIF02–StPIN3 regulatory module that links jasmonate with auxin to modulate apical dominance in potato, providing candidate pathways for designing an ideal multi‐branched plant architecture in potato.
Enshuang Wang, Shahnewaz Begum, S. Jing et al.· Plant, Cell and Environment· 0 citations
These findings uncover a modularly coordinated control of SGAs accumulation and chlorophyll biosynthesis by bifurcation of StCRY1-StHY5 axis, providing a promising strategy to concurrently curb light-induced tuber greening and glycoalkaloids accumulation.
Jun Qin, S. Jing, Shengxuan Liu et al.· The Plant Cell· 0 citations
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