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<jats:p>Non-photochemical quenching (NPQ) is a protective mechanism used by plants to safely dissipate excess absorbed light energy as heat, minimizing photo-oxidative damage. Although the importance of NPQ as a safety valve for photosynthesis is well-known, the physiological and environmental effects of the heat produced remain unclear because the amount of heat produced by NPQ is considered negligible, and its physiological effects have not been directly observed. Here, we calculated the heat produced by NPQ and evaluated its impact on the leaf and global warming based on simplified models. Our evaluation showed that the heat produced by NPQ in a given leaf area is 63.9 W m<jats:sup>−2</jats:sup> under direct sunlight. Under the standard condition, NPQ warms up the leaf at less than 0.1°C, but it could be 1°C under particular conditions with low thermal conductance. We also estimated the thermal radiation of vegetation’s NPQ to be 2.2 W m<jats:sup>−2</jats:sup> par global averaged surface area. It is only 0.55% of the thermal radiation by the Earth’s surface, but still significant in the current climate change response. We further discuss the possible function of NPQ to plant physiology besides the safety valve and provide strategies with artificial modification of the NPQ mechanism to increase food production and mitigate global warming.</jats:p>

<jats:p>RNA-directed DNA methylation (RdDM) is driven by small RNAs (sRNAs) complementary to the nascent transcript of RNA polymerase V (Pol V). sRNAs associated with ARGONAUTE (AGO) proteins are tethered to Pol V mainly by the AGO-hook domain of its subunit NRPE1. We found, by <jats:italic>in silico</jats:italic> analyses, that Pol V strongly colocalizes on chromatin with another AGO-hook protein, SPT6-like (SPT6L), which is a known essential transcription elongation factor of Pol II. Our phylogenetic analysis revealed that SPT6L acquired its AGO-binding capacity already in the most basal streptophyte algae, even before the emergence of Pol V, suggesting that SPT6L might be a driving force behind the RdDM evolution. Since its emergence, SPT6L with the AGO-hook represents the only conserved SPT6 homolog in <jats:italic>Viridiplantae</jats:italic>, implying that the same protein is involved in both Pol II and Pol V complexes. To better understand the role of SPT6L in the Pol V complex, we characterized genomic loci where these two colocalize and uncovered that DNA methylation there is more dynamic, driven by higher levels of sRNAs often from non-canonical RdDM pathways and more dependent on chromatin modifying and remodeling proteins like MORC. Pol V loci with SPT6L are highly depleted in helitrons but enriched in gene promoters for which locally and temporally precise methylation is necessary. In view of these results, we discuss potential roles of multiple AGO-hook domains present in the Pol V complex and speculate that SPT6L mediates <jats:italic>de novo</jats:italic> methylation of naïve loci by interconnecting Pol II and Pol V activities.</jats:p>

<jats:sec><jats:title>Introduction</jats:title><jats:p>Climate change is impacting the wine industry by accelerating ripening processes due to warming temperatures, especially in areas of significant grape production like California. Increasing temperatures accelerate the rate of sugar accumulation (measured in ⁰Brix) in grapes, however this presents a problem to wine makers as flavor profiles may need more time to develop properly. To alleviate the mismatch between sugar accumulation and flavor compounds, growers may sync vine cultivars with climates that are most amenable to their distinct growing conditions. However, the traits which control such cultivar specific climate adaptation, especially for ⁰Brix accumulation rate, are poorly understood. Recent studies have shown that higher rates of fruit development and sugar accumulation are predicted by larger phloem areas in different organs of the plant.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Here we test this phloem area hypothesis using a common garden experiment in the Central Valley of Northern California using 18 cultivars of the common grapevine (<jats:italic>Vitis vinifera</jats:italic>) and assess the grape berry sugar accumulation rates as a function of phloem area in leaf and grape organs. </jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>We find that phloem area in the leaf petiole organ as well as the berry pedicel is a significant predictor of ⁰Brix accumulation rate across 13 cultivars and that grapes from warm climates overall have larger phloem areas than those from hot climates. In contrast, other physiological traits such as photosynthetic assimilation and leaf water potential did not predict berry accumulation rates. </jats:p></jats:sec><jats:sec><jats:title>Discussion</jats:title><jats:p>As hot climate cultivars have lower phloem areas which would slow down brix accumulation, growers may have inadvertently been selecting this trait to align flavor development with sugar accumulation across the common cultivars tested. This work highlights a new trait that can be easily phenotyped (i.e., petiole phloem area) and be used for growers to match cultivar more accurately with the temperature specific climate conditions of a growing region to obtain satisfactory sugar accumulation and flavor profiles.</jats:p></jats:sec>

<jats:p><jats:italic>Arabidopsis thaliana</jats:italic> Mitogen-activated protein Kinase Phosphatase 1 (MKP1) negatively balances production of reactive oxygen species (ROS) triggered by Microbe-Associated Molecular Patterns (MAMPs) through uncharacterized mechanisms. Accordingly, ROS production is enhanced in <jats:italic>mkp1</jats:italic> mutant after MAMP treatment. Moreover, <jats:italic>mkp1</jats:italic> plants show a constitutive activation of immune responses and enhanced disease resistance to pathogens with distinct colonization styles, like the bacterium <jats:italic>Pseudomonas syringae</jats:italic> pv. tomato DC3000, the oomycete <jats:italic>Hyaloperonospora arabidopsidis</jats:italic> Noco2 and the necrotrophic fungus <jats:italic>Plectosphaerella cucumerina</jats:italic> BMM. The molecular basis of this ROS production and broad-spectrum disease resistance controlled by MKP1 have not been determined. Here, we show that the enhanced ROS production in <jats:italic>mkp1</jats:italic> is not due to a direct interaction of MKP1 with the NADPH oxidase RBOHD, nor is it the result of the catalytic activity of MKP1 on RBHOD phosphorylation sites targeted by BOTRYTIS INDUCED KINASE 1 (BIK1) protein, a positive regulator of RBOHD-dependent ROS production. The analysis of <jats:italic>bik1 mkp1</jats:italic> double mutant phenotypes suggested that MKP1 and BIK1 targets are different. Additionally, we showed that phosphorylation residues stabilizing MKP1 are essential for its functionality in immunity. To further decipher the molecular basis of disease resistance responses controlled by MKP1, we generated combinatory lines of <jats:italic>mkp1-1</jats:italic> with plants impaired in defensive pathways required for disease resistance to pathogen: <jats:italic>cyp79B2 cyp79B3</jats:italic> double mutant defective in synthesis of tryptophan-derived metabolites, <jats:italic>NahG</jats:italic> transgenic plant that does not accumulate salicylic acid, <jats:italic>aba1-6</jats:italic> mutant impaired in abscisic acid (ABA) biosynthesis, and <jats:italic>abi1 abi2 hab1</jats:italic> triple mutant impaired in proteins described as ROS sensors and that is hypersensitive to ABA. The analysis of these lines revealed that the enhanced resistance displayed by <jats:italic>mkp1-1</jats:italic> is altered in distinct mutant combinations: <jats:italic>mkp1-1 cyp79B2 cyp79B3</jats:italic> fully blocked <jats:italic>mkp1-1</jats:italic> resistance to <jats:italic>P. cucumerina</jats:italic>, whereas <jats:italic>mkp1-1 NahG</jats:italic> displays partial susceptibility to <jats:italic>H. arabidopsidis</jats:italic>, and <jats:italic>mkp1-1 NahG</jats:italic>, <jats:italic>mkp1-1 aba1-6</jats:italic> and <jats:italic>mkp1-1 cyp79B2 cyp79B3</jats:italic> showed compromised resistance to <jats:italic>P. syringae</jats:italic>. These results suggest that MKP1 is a component of immune responses that does not directly interact with RBOHD but rather regulates the status of distinct defensive pathways required for disease resistance to pathogens with different lifestyles.</jats:p>

<jats:p>Artemisinin biosynthesis, unique to <jats:italic>Artemisia annua</jats:italic>, is suggested to have evolved from the ancestral costunolide biosynthetic pathway commonly found in the Asteraceae family. However, the evolutionary landscape of this process is not fully understood. The first oxidase in artemisinin biosynthesis, CYP71AV1, also known as amorpha-4,11-diene oxidase (AMO), has specialized from ancestral germacrene A oxidases (GAOs). Unlike GAO, which exhibits catalytic promiscuity toward amorpha-4,11-diene, the natural substrate of AMO, AMO has lost its ancestral activity on germacrene A. Previous studies have suggested that the loss of the GAO copy in <jats:italic>A. annua</jats:italic> is responsible for the abolishment of the costunolide pathway. In the genome of <jats:italic>A. annua</jats:italic>, there are two copies of AMO, each of which has been reported to be responsible for the different product profiles of high- and low-artemisinin production chemotypes. Through analysis of their tissue-specific expression and comparison of their sequences with those of other GAOs, it was discovered that one copy of AMO (AMOHAP) exhibits a different transcript compared to the reported artemisinin biosynthetic genes and shows more sequence similarity to other GAOs in the catalytic regions. Furthermore, in a subsequent <jats:italic>in vitro</jats:italic> enzymatic assay, the recombinant protein of AMOHAP unequivocally demonstrated GAO activity. This result clearly indicates that AMOHAP is a GAO rather than an AMO and that its promiscuous activity on amorpha-4,11-diene has led to its misidentification as an AMO in previous studies. In addition, the divergent expression pattern of AMOHAP compared to that of the upstream germacrene A synthase may have contributed to the abolishment of costunolide biosynthesis in <jats:italic>A. annua</jats:italic>. Our findings reveal a complex evolutionary landscape in which the emergence of a new metabolic pathway replaces an ancestral one.</jats:p>

<jats:p>Plants from the <jats:italic>Sceletium</jats:italic> genus (Aizoaceae) have been traditionally used for millennia by the Khoe and Khoen people in southern Africa, as an appetite suppressant as well as a mood elevator. In more recent times, this mood-elevating activity has been commercialised in the South African natural products industry for the treatment of anxiety and depression, with several products available both locally and abroad. Research on this species has seen rapid growth with advancements in analytical and pharmacological tools, in an effort to understand the composition and biological activity. The Web of Science (WoS) database was searched for articles related to ‘Sceletium’ and ‘Mesembrine’. These data were additionally analysed by bibliometric software (VOSviewer) to generate term maps and author associations. The thematic areas with the most citations were South African Traditional Medicine for mental health (110) and anxiolytic agents (75). Pioneer studies in the genus focused on chemical structural isolation, purification, and characterisation and techniques such as thin layer chromatography, liquid chromatography (HPLC, UPLC, and more recently, LC-MS), gas chromatography mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) to study mesembrine alkaloids. Different laboratories have used a diverse range of extraction and preanalytical methods that became routinely favoured in the analysis of the main metabolites (mesembrine, mesembranol, mesembranone, and Sceletium A4) in their respective experimental settings. In contrast with previous reviews, this paper identified gaps in the research field, being a lack of toxicology assays, a deficit of clinical assessments, too few bioavailability studies, and little to no investigation into the minor alkaloid groups found in <jats:italic>Sceletium</jats:italic>. Future studies are likely to see innovations in analytical techniques like leaf spray mass spectrometry and direct analysis in real-time ionisation coupled with high-resolution time-of-flight mass spectrometry (DART-HR-TOF-MS) for rapid alkaloid identification and quality control purposes. While <jats:italic>S. tortuosum</jats:italic> has been the primary focus, studying other <jats:italic>Sceletium</jats:italic> species may aid in establishing chemotaxonomic relationships and addressing challenges with species misidentification. This research can benefit the nutraceutical industry and conservation efforts for the entire genus. At present, little to no pharmacological information is available in terms of the molecular physiological effects of mesembrine alkaloids in medical clinical settings. Research in these fields is expected to increase due to the growing interest in <jats:italic>S. tortuosum</jats:italic> as a herbal supplement and the potential development of mesembrine alkaloids into pharmaceutical drugs.</jats:p>

<jats:p>The plant pathogenic fungus <jats:italic>Blumeria graminis</jats:italic> f. sp. <jats:italic>tritici</jats:italic> infects wheat and reduces its yield. The policy of reducing fertilizer and biocide use in sustainable agriculture has prompted researchers to develop more green and efficient management strategies. In this study, a novel nanoprotective membrane (kaolin-nano titanium dioxide-liquid paraffin, referred to as KTP) that could effectively prevent powdery mildew of wheat was prepared by using 1 g/L kaolin, 2 g/L nanotitanium dioxide and 8% (v/v) liquid paraffin. The prevention and control effects of KTP spraying in advance in the pot and field experiments were 98.45% and 83.04%, respectively. More importantly, the weight of 1000 grains of wheat pretreated with KTP was 2.56 g higher than that of wheat infected with powdery mildew, significantly improving wheat yield. KTP delayed the germination of powdery mildew spores on the leaf surface, and inhibited the formation of mycelia. In addition, KTP did not affect the growth of wheat or the survival of earthworms. KTP nanoprotective membrane are a green and safe prevention and control materials that are which is expected to be widely used in agriculture to control wheat powdery mildew.</jats:p>

<jats:p>The brown planthopper (BPH) is the most destructive insect pest that threatens rice production globally. Developing rice varieties incorporating BPH-resistant genes has proven to be an effective control measure against BPH. In this study, we assessed the resistance of a core collection consisting of 502 rice germplasms by evaluating resistance scores, weight gain rates and honeydew excretions. A total of 117 rice varieties (23.31%) exhibited resistance to BPH. Genome-wide association studies (GWAS) were performed on both the entire panel of 502 rice varieties and its subspecies, and 6 loci were significantly associated with resistance scores (P value &amp;lt; 1.0e<jats:sup>-8</jats:sup>). Within these loci, we identified eight candidate genes encoding receptor-like protein kinase (RLK), nucleotide-binding and leucine-rich repeat (NB-LRR), or LRR proteins. Two loci had not been detected in previous study and were entirely novel. Furthermore, we evaluated the predictive ability of genomic selection for resistance to BPH. The results revealed that the highest prediction accuracy for BPH resistance reached 0.633. As expected, the prediction accuracy increased progressively with an increasing number of SNPs, and a total of 6.7K SNPs displayed comparable accuracy to 268K SNPs. Among various statistical models tested, the random forest model exhibited superior predictive accuracy. Moreover, increasing the size of training population improved prediction accuracy; however, there was no significant difference in prediction accuracy between a training population size of 737 and 1179. Additionally, when there existed close genetic relatedness between the training and validation populations, higher prediction accuracies were observed compared to scenarios when they were genetically distant. These findings provide valuable resistance candidate genes and germplasm resources and are crucial for the application of genomic selection for breeding durable BPH-resistant rice varieties.</jats:p>

<jats:p>Naturally colored cotton (NCC) offers an environmentally friendly fiber for textile applications. Processing white cotton fiber into textiles requires extensive energy, water, and chemicals, whereas processing of NCC skips the most polluting activity, scouring-bleaching and dyeing; therefore, NCC provides an avenue to minimize the harmful impacts of textile production. NCC varieties are suitable for organic agriculture since they are naturally insect and disease-resistant, salt and drought-tolerant. Various fiber shades, ranging from light green to tan and brown, are available in the cultivated NCC (<jats:italic>Gossypium hirsutum</jats:italic> L.) species. The pigments responsible for the color of brown cotton fiber are proanthocyanidins or their derivatives synthesized by the flavonoid pathway. Due to pigments, the NCC has excellent ultraviolet protection properties. Some brown cotton varieties exhibited superior thermal resistance of fiber that can be used to make fabrics with enhanced flame retardancy. Here, we review molecular mechanisms involved in the pigment production of brown cotton and challenges in breeding NCC varieties with a wide range of colors but without penalty in fiber quality. Also, we discuss opportunities for NCC with flame-retarding properties in textile applications.</jats:p>

<jats:p>In our earlier works, we have shown that the rate-limiting steps, associated with the dark-to-light transition of Photosystem II (PSII), reflecting the photochemical activity and structural dynamics of the reaction center complex, depend largely on the lipidic environment of the protein matrix. Using chlorophyll-<jats:italic>a</jats:italic> fluorescence transients (ChlF) elicited by single-turnover saturating flashes, it was shown that the half-waiting time (Δ<jats:italic>τ</jats:italic><jats:sub>1/2</jats:sub>) between consecutive excitations, at which 50% of the fluorescence increment was reached, was considerably larger in isolated PSII complexes of <jats:italic>Thermostichus</jats:italic> (<jats:italic>T.</jats:italic>) <jats:italic>vulcanus</jats:italic> than in the native thylakoid membrane (TM). Further, it was shown that the addition of a TM lipid extract shortened Δ<jats:italic>τ</jats:italic><jats:sub>1/2</jats:sub> of isolated PSII, indicating that at least a fraction of the ‘missing’ lipid molecules, replaced by detergent molecules, caused the elongation of Δ<jats:italic>τ</jats:italic><jats:sub>1/2</jats:sub>. Here, we performed systematic experiments to obtain information on the nature of TM lipids that are capable of decreasing Δ<jats:italic>τ</jats:italic><jats:sub>1/2</jats:sub>. Our data show that while all lipid species shorten Δ<jats:italic>τ</jats:italic><jats:sub>1/2</jats:sub>, the negatively charged lipid phosphatidylglycerol appears to be the most efficient species – suggesting its prominent role in determining the structural dynamics of PSII reaction center.</jats:p>