In conversation with Dr. Jie Yang

Dr. Jie Yang Prof. Shouchuang Wang 1. What is your personal and educational background, and how did you become interested in plant biology? From my master's through my Ph.D., my whole academic arc has stayed anchored at Hainan University: I began with biochemistry and molecular biology, then stepped into Prof. Wang's team to decode the biosynthesis, regulation, and function of tomato specialized metabolites. My curiosity about plants sprouted in college and took off during my master's. Along the way, I have been continually amazed by how plant life operates, how a single seed develops into an entire organism, how plants endure extreme environments, and how they communicate, cooperate, and compete with one another. Plants are non-human yet highly intelligent life forms, governed by a calm, emotionless order. They answer the questions ‘What do I perceive?’ and ‘How do I survive?’ in a chemical language using metabolites, and a physical language with turgor, vibration, and negative pressure. 2. What inspired you to pursue research at the intersection of plant stress physiology and molecular genetics? Plants can neither speak nor run; they can only cry out ‘I'm in pain!’ through stress responses like stomata snap shut, ROS bursts, and transcripts sky-rocketing within minutes. These physiological symptoms and molecular events are almost instantaneous and quantifiable. Stress physiology captures the plant's authentic agony; molecular biology is the key that unlocks how that agony arises and is answered. Working at the crossroads of these two fields is like clutching both ‘cause’ and ‘effect’ in one fist, forcing the bare mechanism of the event to reveal itself. 3. What are the main findings of your paper? In this study we first used mGWAS to identify a polyamine-modification and transport gene cluster on tomato chromosome 8; by tuning endogenous and exogenous polyamine (and their conjugates) levels, this cluster acts as a front-line responder to salt stress. We further show that the polyamine transporter SlPUT3 physically interacts with the H2O2 transporter SlPIP2;4, thereby coupling polyamine flux to ROS homeostasis and stress response. 4. Would you explain what mGWAS is and the importance of this methodology for your work? mGWAS is a metabolite-based genome-wide association study that treats metabolite abundance as a quantitative trait. By correlating these biochemical phenotypes with whole-genome resequencing data, we fish out the SNPs that answer ‘why is this metabolite high or low?’—anchoring chemical variation to genetic differences. For me and our team this approach has become a workhorse: we have already used it to pinpoint the key polymorphisms controlling polyamines, phenolamides, steroidal glycoalkaloids, flavonoids and more, turning biochemical curiosity into harvestable genes. 5. Your work highlights a polyamine transport/modification gene cluster linked to salt tolerance; what was most surprising about the natural variation you uncovered? Although previous studies have implicated polyamines in salt-stress responses, most focused on biosynthesis enzymes; transport proteins and modification enzymes—especially those organized as gene clusters—remained largely unexplored. Consequently, we initially assumed that polyamine accumulation in plants follows a ‘the more, the better’ paradigm. Subsequent analyses revealed, however, that dynamic homeostasis is far more critical than static abundance. The reaction releases H2O2, just enough to serve as a signal rather than a death sentence. Making the loop even tighter, the transporter SlPUT3 partners with the aquaporin SlPIP2;4 to fine-tune that H2O2 dose, shielding cells from oxidative damage while still sounding the stress alarm. Watching the plant orchestrate this self-balancing act left me speechless—precision engineering without an engineer. 6. How do you see this gene cluster influencing future efforts in breeding or engineering salt-tolerant tomatoes and other crops? Tomato is a horticultural pillar of China, yet its fresh-market price continues to climb, making improvements in yield, flavor, and stress tolerance a national priority. Our study demonstrates that exogenous application or endogenous modulation of polyamine levels enhances fruit set and biomass under saline–alkaline conditions, and we anticipate that analogous strategies will translate to other staple crops. Plant metabolic gene clusters have emerged as efficient regulatory units that synchronize the expression of entire biochemical pathways, thereby maximizing flux while minimizing energy consumption and by-product formation. Elucidating and engineering such clusters therefore represents a powerful approach for accelerating climate-resilient molecular breeding across diverse crop species. 7. In practical terms, what are the prospects for translating these findings into field-ready varieties? Are there barriers you anticipate? Our present work remains fundamentally oriented toward molecular biology and has yet to be evaluated under field conditions. Nevertheless, the mechanism we have delineated—namely, that exogenous foliar application of polyamines can alleviate damage imposed by abiotic stresses—already provides a feasible protocol for on-farm deployment. In parallel, we have surveyed natural variation in the target gene cluster across both wild and cultivated tomato accessions and identified superior alleles (unpublished); our next step is to introgress these alleles into elite germplasm and deploy them in marker-assisted or genome-edited breeding programs, thereby translating our findings from the bench to the soil. From a practical standpoint, crops in the field are typically confronted by multiple, simultaneous stresses (e.g., salinity + drought + heat) that often erode the benefits conferred by single-gene solutions. Editing an entire metabolic gene cluster, however, can generate compensatory interactions that dampen these trade-offs, effectively ‘rescuing’ performance under combination stress. An additional caveat is that we have not yet systematically evaluated the impact of elevated polyamine levels on fruit quality; the risk that enhanced stress tolerance might compromise flavor, texture, or consumer acceptance remains an open question. Future breeding efforts must therefore integrate high-throughput phenotyping for both stress resilience and quality traits to ensure that resilient lines retain market value. 8. Polyamines play multiple physiological roles, how do you think manipulating their transport/metabolism might affect tolerance to stresses beyond salinity? Polyamines function not merely as protective metabolites but also as pivotal signaling molecules. By modulating the hallmarks of abiotic stress like ion disequilibrium, protein denaturation, ROS bursts, and membrane lipid peroxidation, polyamines confer systemic tolerance. Yet accumulation beyond a discrete threshold is phytotoxic, as we and others have demonstrated. Consequently, fine-tuning polyamine content through dedicated transporters and modification enzymes (ensuring that these metabolites appear in the correct organelle, at the right time and at an optimal concentration) transforms them from simple salt-stress buffers into broad-spectrum adaptive modules. 9. Given the complexity of stress responses, what experimental approaches do you see as most promising for dissecting downstream networks linked to this cluster? Proximity-labeling mass spectrometry can map the ‘social network’ of key proteins. I plan to apply this strategy to our gene-cluster project to systematically resolve the cluster-specific protein–protein interaction landscape. Subsequently, I will couple this with DARTS (Drug Affinity Responsive Target Stability) to fish for proteins that directly engage polyamines, aiming to identify receptors, modification enzymes, and transporters that bind these metabolites in vivo. 10. What do you hope other researchers take away from this study in terms of how we investigate and harness natural genetic variation for stress tolerance? Since wild tomatoes originated from the harsh Andean highlands, they possessed strong tolerance to multiple abiotic stresses. However, human-driven selection during domestication led to the loss of numerous stress-resilience loci, including those governing specialized-metabolite abundance. Integrating population-wide natural variation between wild and cultivated accessions with high-throughput metabolite profiling through mGWAS provides a powerful strategy to identify genomic regions underlying the synthesis, modification, and transport of key metabolites. It should be emphasized that mGWAS typically resolves a haplotype block rather than a single causal gene; therefore, follow-up integration of public databases, metabolic network modeling, and functional assays remains indispensable for pinpointing the precise gene(s) responsible for metabolic variation.