Transcription factor OsMYB2 triggers amino acid transporter OsANT1 expression to regulate rice growth and salt tolerance

Multi-omics-Based Construction of ncRNA-Gene-Metabolite Networks Provides New Insights Into Metabolic Regulation Under Salt Stress in Rice

Rice (Oryza sativa L.), one of the most vital staple crops globally, suffers severe yield losses due to metabolic dysregulation under salt stress. However, the systemic mechanisms by which non-coding RNAs (ncRNAs) coordinately regulate metabolic reprogramming remain elusive, and the genotype-specific regulatory networks in salt-tolerant cultivars are poorly characterized. To address this, we performed metabolomic analysis using ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) across different rice varieties under salt stress, identifying 327 metabolites, with the most notable fluctuations observed in lipids, polyamines, and phenolamides. The salt-tolerant variety Pokkali exhibited 51.96% and 31.37% fewer differentially accumulated metabolites (DAMs) in the shoots and roots respectively, compared to the salt-sensitive variety Nipponbare (NIP), which explains its superior salt-tolerant phenotype from a metabolic homeostasis perspective. Transcriptome profiling revealed 18,597 differentially expressed genes (DEGs), with 70.8% showing genotype-specific expression patterns. Pokkali-specific DEGs were markedly enriched in salt-responsive pathways, including reactive nitrogen species scavenging and ion compartmentalization. By integrating long non-coding RNA (lncRNA) and microRNA (miRNA) sequencing data, we constructed a four-tiered regulatory network comprising 6,201 DEGs, 458 miRNAs, 970 DElncRNAs, and 177 metabolites. In the regulatory network, Osa-miR408-3p was identified as a negative regulator of Os03 g0709300 expression. Network analysis revealed that 21 polyamine and phenolamides biosynthesis-related genes were co-regulated by eight miRNAs, each forming a feedback loop with 2-11 lncRNAs. This study constructed a four-way cascade of "lncRNA-miRNA-mRNA-metabolite", and proposed a new concept of ncRNA-mediated "network regulation instead of single-gene effect".

Harnessing neo-domestication of wild pigmented rice for enhanced nutrition and sustainable agriculture

Advances in precision gene editing have enabled the rapid domestication of wild crop relatives, a process known as neo-domestication. During domestication, breeding rice for maximum productivity under optimal growth conditions reduced genetic diversity, eliminating variants for stress tolerance and grain nutrients. Wild rice varieties have rich genetic diversity, including variants for disease resistance, stress tolerance, and grain nutritional quality. For example, the grain of pigmented wild rice has abundant antioxidants (anthocyanins, proanthocyanidins, and flavonoids), but low yield, poor plant architecture, and long life cycle limit its cultivation. In this review, we address the neo-domestication of wild pigmented rice, focusing on recent progress, CRISPR-Cas editing toolboxes, selection of key candidate genes for domestication, identifying species with superior potential via generating genomic and multi-omics resources, efficient crop transformation methods and highlight strategies for the promotion and application pigmented rice. We also address critical outstanding questions and potential solutions to enable efficient neo-domestication of wild pigmented rice and thus enhance food security and nutrition.

Molecular and Physiological Responses of Plants that Enhance Cold Tolerance

Low-temperature stress, including chilling and freezing injuries, significantly impacts plant growth in tropical and temperate regions. Plants respond to cold stress by activating mechanisms that enhance freezing tolerance, such as regulating photosynthesis, metabolism, and protein pathways and producing osmotic regulators and antioxidants. Membrane stability is crucial, with cold-resistant plants exhibiting higher lipid unsaturation to maintain fluidity and normal metabolism. Low temperatures disrupt reactive oxygen species (ROS) metabolism, leading to oxidative damage, which is mitigated by antioxidant defenses. Hormonal regulation, involving ABA, auxin, gibberellins, and others, further supports cold adaptation. Plants also manage osmotic balance by accumulating osmotic regulators like proline and sugars. Through complex regulatory pathways, including the ICE1-CBF-COR cascade, plants optimize gene expression to survive cold stress, ensuring adaptability to freezing conditions. This study reviews the recent advancements in genetic engineering technologies aimed at enhancing the cold resistance of agricultural crops. The goal is to provide insights for further improving plant cold tolerance and developing new cold-tolerant varieties.

The Regulation of ROS and Phytohormones in Balancing Crop Yield and Salt Tolerance

Salinity affects crop growth and productivity, and this stress can be increased along with drought or high temperature stresses and poor irrigation management. Cultivation of salt-tolerant crops plays a critical role in enhancing crop yield under salt stress. In the past few decades, the mechanisms of plant adaptation to salt stress have been described, especially relying on ionic homeostasis, reactive oxygen species (ROS) scavenging, and phytohormone signaling. The studies of these molecular mechanisms have provided a basis for breeding new salt-tolerant crop germplasm and have facilitated the entry into the era of molecular breeding of salt-tolerant crops. In this review, we outline the recent progress in the molecular regulations underlying crop salt tolerance, focusing on the double-edged sword effect of ROS, the regulatory role of phytohormones, and the trade-off effects of ROS and phytohormones between crop yield and salt tolerance. A future challenge is to identify superior alleles of key salt-tolerant genes that will accelerate the breeding of high-yield and salt-tolerant varieties.