Agriculture crop development and production may be hampered in the modern era because of the increasing prevalence of ecological problems around the world. In the last few centuries, plant and agrarian scientific experts have shown significant progress in promoting efficient and eco-friendly approaches for the green synthesis of nanoparticles (NPs), which are noteworthy due to their unique physio-biochemical features as well as their possible role and applications. They are thought to be powerful sensing molecules that regulate a wide range of significant physiological and biochemical processes in plants, from germination to senescence, as well as unique strategies for coping with changing environmental circumstances. This review highlights current knowledge on the plant extract-mediated synthesis of NPs, as well as their significance in reprogramming plant traits and ameliorating abiotic stresses. Nano particles-mediated modulation of phytohormone content in response to abiotic stress is also displayed. Additionally, the applications and limitations of green synthesized NPs in various scientific regimes have also been highlighted.

Summary: Effector-triggered immunity (ETI) is a central component of host defense, but whether all cell types execute ETI similarly remains unknown. We combined chemically imposed immune activation with single-cell transcriptomics to profile ETI responses across all leaf cell types in Arabidopsis. Despite uniform ETI perception, we find striking divergence between transcriptional outputs: a core set of defense genes is broadly induced, while distinct cell types activate specialized immune modules. We infer that downstream immune execution is shaped not only by immune receptor activation, but also by cell identity and its associated transcriptional regulatory context, including local transcription factor availability and chromatin accessibility. We further demonstrate that transcriptional regulators preferentially induced in epidermal cells are required to restrict invasion by non-adapted pathogens. Their absence permits pathogen entry into deeper tissues despite intact recognition, revealing a spatial division of immune functions. Our findings uncover a layered immune architecture in plants, challenges the assumption of uniform immune execution, and provides a framework for exploring cell-type-specific resistance logic in multicellular hosts.

The rising rate of heavy metal contamination due to industrialization, urbanization, and modern agricultural practices has posed unparalleled problems for natural ecosystems and food chains either through direct ingestion or contact with environmental contamination (McLaughlin et al. 1999; Miransari 2011). These heavy metals are non-biodegradable components that frequently concentrate in the root environment due to excessive use of unplanned municipal and industrial wastewater, sewage sludge, pesticides, and chemical fertilizers (Pandey and Pandey 2009; El-Ramady et al. 2015). Some of these heavy metals such as Pb, Cd, Cr, As, and Hg do not take part in any known physiological functions and are very toxic even at very low concentrations (Ernst et al. 2008; Garzón et al. 2011; Chong-qing et al. 2013). However, the essential elements such as Fe, Mn, Ni, Zn, Co, and Cu are required for the normal growth and metabolic processes of plants, but they become toxic when their concentrations exceed their permissible limits (Blaylock and Huang 2000; Sebastiani et al. 2004). The most widespread effect of this metal toxicity on plants is reduction in growth including low biomass accumulation, leaf chlorosis, necrosis, inhibition of seed germination, photosynthesis, altered water balance and nutrient availability, and senescence which ultimately leads to plant death (Carrier et al. 2003; DalCorso et al. 2010). An excess of metals alters various physio-biochemical processes by the stimulation of ROS, enzyme inactivation, blocking functional groups of metabolically important molecules, disrupting membrane integrity, and 70displacing essential metal ions from specific binding sites (Rascio and Navari Izzo 2011; Villiers et al. 2012). Therefore, this review is focused on a physiological and molecular approach to metal toxicity, ROS production, avoidance, and scavenging in the light of heavy metal stress in plants, with special attention on the emrging role of osmoprotectants as antioxidants.

Abscisic acid (ABA) regulates plant responses to stress and influences the differentiation of root barrier cell types, such as the endodermis and exodermis. Despite the importance of the exodermis in limiting water and solute fluxes, its regulation remains poorly understood in legumes. Here, we characterize the ABA-induced suberization and lignification of root tissues across eight galegoid legumes to identify exodermis-forming species in the clade. Chickpea deposited suberin lamella specifically in the outermost cortex and formed a functional apoplastic barrier, i.e. an exodermis. Transcriptomics of chickpea roots revealed ABA-induced programs that were temporally separated, specifically, a rapid program with the general ABA response, and a delayed programs of suberin and lignin biosynthesis. We identified WRKY and MYB transcription factors that putatively link the ABA response to the suberin biosynthesis, and using single-cell RNA-seq of chickpea roots we inferred an exodermis-expressed WRKY-MYB regulatory unit upstream of the suberin biosynthetic genes. Transactivation assays supported an ABA-dependent transcription factor activity upstream of suberin biosynthesis pathway in chickpea. Our results reveal a cell-type specific transcription factor hierarchy that coordinates hormone perception into an important mechanism of root plasticity in legumes.

Summary: Excessive activation of effector-triggered immunity (ETI) in plants inhibits plant growth and activates cell death. ETI mediated by intracellular Toll/Interleukin-1 receptor/Resistance protein (TIR) nucleotide-binding leucine-rich-repeat receptors (NLRs) involves two partially redundant signalling nodes in Arabidopsis, EDS1-PAD4-ADR1 and EDS1-SAG101-NRG1. Genetic and transcriptomic analyses show that EDS1-PAD4-ADR1 primarily enhances the immune component abundance and is critical for limiting pathogen growth, whereas EDS1-SAG101-NRG1 mainly activates the hypersensitive cell death response (HR) but is dispensable for immune priming. This study enhances our understanding of the distinct contributions of these two signalling modules to ETI and suggests potential strategies for improving disease resistance in crops without compromising yield.

Summary: Effector-triggered immunity (ETI) is a major defence strategy in plants and is frequently associated with the hypersensitive response (HR), a localized form of programmed cell death long assumed to be essential for pathogen resistance. However, the causal relationship between HR and effective immunity remains unresolved. We show that the Arabidopsis cbp60g sard1 double mutant exhibits exaggerated ETI-associated HR but only partial resistance to bacterial and oomycete pathogens, thereby genetically uncoupling cell death from disease resistance without pleiotropic defects. Genome-wide transcriptome profiling reveals that the absence of CBP60g and SARD1 disrupts the balance between immune activators and suppressors, including reduced induction of the Nudix hydrolase NUDT7. Overexpression of NUDT7 diminishes but does not abolish the heightened HR phenotype in cbp60g sard1 mutant, indicating that multiple negative regulators act redundantly to restrain immune-associated cell death. These findings demonstrate that HR is not an obligatory determinant of effective resistance and provide mechanistic insight into how plants coordinate transcriptional networks to balance pathogen defence with the containment of host cell death. By refining the relationship between HR and immunity, this work challenges a long-standing paradigm in plant biology and advances our understanding of immune regulation.