The Plant Journal最新文献

Retraction: L. Ramírez Gonzales, L. Shi, S. Bergonzi Bergonzi, M. Oortwijn, J. M. Franco-Zorrilla, R. Solano-Tavira, R. G. F. Visser, J. A. Abelenda, C. W. B. Bachem, "Potato CYCLING DOF FACTOR 1 and its lncRNA Counterpart StFLORE Link Tuber Development and Drought Response," The Plant Journal 105, no. 4 (2021): 855-869. https://doi.org/10.1111/tpj.15093. The above article, published online on 21 November 2020, in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors; the journal Editor-in-Chief, Katherine Denby; Society for Experimental Biology (SEB); and John Wiley & Sons Ltd. The authors reported that they had discovered errors in the 35S:StFORE construct which compromise the conclusions. The authors have also not been able to repeat the anti-phasic expression profile of the StFLORE IncRNA transcript following numerous independent experiments post-publication. While the authors confirmed that other data reported in the article remain valid, all parties agree that the concerns listed fundamentally compromise the conclusions reported in the article, which necessitates retraction.

Domestication has dramatically increased crop size and biomass, reflecting the enhanced accumulation of photosynthates. However, we still lack solid empirical data on the impacts of domestication on photosynthetic rates at different light intensities and on leaf anatomy, and of the relationships of photosynthesis with aboveground biomass. In this study, we measured the photosynthetic rate at three photosynthetic photon flux densities of 2000 (high), 1000 (moderate) and 400 μmol m^-2 sec^-1 (low light intensity), dark respiration, relative chlorophyll content (SPAD), leaf morphology, and aboveground biomass in 40 wild, 91 semiwild, and 42 domesticated cotton genotypes. The study was replicated for two years (growing years 2018 and 2019). During the first domestication stage (transition from wild to semiwild genotypes), domestication led to higher photosynthetic rates measured under high light intensity, higher SPAD, larger leaf area (LA), and lower leaf mass per unit area (LMA), contributing to greater aboveground biomass accumulation in both study years. During the second domestication stage (transition from semiwild to domesticated genotypes), domestication significantly enhanced photosynthesis under low light intensity and reduced LMA, which were associated with increased aboveground biomass in both study years. In conclusion, photosynthesis improvement at different light intensities has been a gradual domestication phase specific process with the rate of photosynthesis enhanced under high light during the first domestication stage, and under low light during the second domestication stage. We argue that these differences reflect a higher proportion of LA photosynthesizing under low light due to enhanced canopy expansion at the second domestication stage.

Cyclic electron transport around photosystem I (PSI) is essential for the protection of the photosynthetic apparatus in plants under diverse light conditions. This process is primarily mediated by Proton Gradient Regulation 5 protein/Proton Gradient Regulation 5-like photosynthetic phenotype 1 protein (PGR5/PGRL1) and NADH dehydrogenase-like complex (NDH). In angiosperms, NDH interacts with two PSI complexes through distinct monomeric antennae, LHCA5 and LHCA6, which is crucial for its higher stability under variable light conditions. This interaction represents an advanced evolutionary stage and offers limited insight into the origin of the PSI-NDH supercomplex in evolutionarily older organisms. In contrast, the moss Physcomitrium patens (Pp), which retains the lhca5 gene but lacks the lhca6, offers a glimpse into an earlier evolutionary stage of the PSI-NDH supercomplex. Here we present structural evidence of the Pp PSI-NDH supercomplex formation by single particle electron microscopy, demonstrating the unique ability of Pp to bind a single PSI in two different configurations. One configuration closely resembles the angiosperm model, whereas the other exhibits a novel PSI orientation, rotated clockwise. This structural flexibility in Pp is presumably enabled by the variable incorporation of LHCA5 within PSI and is indicative of an early evolutionary adaptation that allowed for greater diversity at the PSI-NDH interface. Our findings suggest that this variability was reduced as the structural complexity of the NDH complex increased in vascular plants, primarily angiosperms. This study not only clarifies the evolutionary development of PSI-NDH supercomplexes but also highlights the dynamic nature of the adaptive mechanisms of plant photosynthesis.

Monomeric flavan-3-ols and their oligomeric forms, proanthocyanidins (PAs), are closely related to the bitterness of tea beverages. Monomeric flavan-3-ols are characteristic flavor compounds in tea. Increasing the content of PAs and anthocyanins enhances the resistance of tea plants to pathogen invasion but decreases the quality of tea beverages. MATE family transporters play a critical role in transferring monomeric flavan-3-ols and anthocyanins into vacuoles for storage or subsequent condensation into PAs. Their activities modulate the ratio of monomeric flavan-3-ols to PAs and increase anthocyanin content in tea plants. In this study, it was observed that the gene expression and protein phosphorylation level of the MATE transporter CsTT12, a vacuole-localized flavonoid transporter, were notably upregulated following exogenous sucrose treatment, promoting PA synthesis in tea plants. Further analysis revealed that overexpression of CsTT12 and CsTT12^S17D significantly increased the content of anthocyanins and PAs in plants, whereas CsTT12^S17A did not. In CsTT12 knockdown plants, PA's accumulation decreased significantly, while monomeric catechin content increased. Moreover, phosphorylation modification enhanced the vacuolar membrane localization of CsTT12, whereas dephosphorylation weakened its vacuolar membrane localization. This study uncovers the crucial role of phosphorylation in flavonoid biosynthesis and provides insights into balancing quality improvements and resistance enhancement.

Tartary buckwheat is known for its ability to adapt to intricate growth conditions and to possess robust stress-resistant properties. Nevertheless, it remains vulnerable to drought stress, which can lead to reduced crop yield. To identify potential genes involved in drought resistance, a genome-wide association study on drought tolerance in Tartary buckwheat germplasm was conducted. A gene encoding pectin methylesterase inhibitors protein (FtPMEI13) was identified, which is not only associated with drought tolerance but also showed induction during drought stress and abscisic acid (ABA) treatment. Further analysis revealed that overexpression of FtPMEI13 leads to improved drought tolerance by altering the activities of antioxidant enzymes and the levels of osmotically active metabolites. Additionally, FtPMEI13 interacts with pectin methylesterase (PME) and inhibits PME activity in response to drought stress. Our results suggest that FtPMEI13 may inhibit the activity of FtPME44/FtPME61, thereby affecting pectin methylesterification in the cell wall and modulating stomatal closure in response to drought stress. Yeast one-hybrid, dual-luciferase assays, and electrophoretic mobility shift assays demonstrated that an ABA-responsive transcription factor FtbZIP46, could bind to the FtPMEI13 promoter, enhancing FtPMEI13 expression. Further analysis indicated that Tartary buckwheat accessions with the genotype resulting in higher FtPMEI13 and FtbZIP46 expression exhibited higher drought tolerance compared to the others. This suggests that this genotype has potential for application in Tartary buckwheat breeding. Furthermore, the natural variation of FtPMEI13 was responsible for decreased drought tolerance during Tartary buckwheat domestication. Taken together, these results provide basic support for Tartary buckwheat breeding for drought tolerance.

Rhythmic oscillation of biological processes helps organisms adapt their physiological responses to the most appropriate time of the day. Chromatin remodeling has been described as one of the molecular mechanisms controlling these oscillations. The importance of these changes in transcriptional activation as well as in the maintenance of heterochromatic regions has been widely demonstrated. However, little is still known on how diurnal changes can impact the global status of chromatin modifications and, hence, control gene expression. In plants, the repressive mark H3K27me1, deposited by ARABIDOPSIS TRITHORAX-RELATED PROTEIN 5 and 6 (ATXR5 and 6) methyltransferases, is largely associated with transposable elements but also covers lowly expressed genes. Here we show that this histone modification is preferentially deposited during the night. In euchromatic regions, it is found along the bodies of DNA damage response genes (DDR), where it is needed for their proper expression. The absence of H3K27me1 translates into an enhanced expression of DDR genes that follows a rhythmic oscillation pattern. This evidences a link between chromatin modifications and their synchronization with the diurnal cycle in order to accurately modulate the activation of biological processes to the most appropriate time of the day.

Manipulating plant height is an essential component of crop improvement. Plant height was generally reduced through breeding in wheat, rice, and sorghum to resist lodging and increase grain yield but kept high for bioenergy crops. Here, we positionally cloned a plant height quantitative trait locus (QTL) qHT7.1 as a MYB transcription factor controlling internode elongation, cell proliferation, and cell morphology in sorghum. A 740 bp transposable element insertion in the intronic region caused a partial mis-splicing event, generating a novel transcript that included an additional exon and a premature stop codon, leading to short plant height. The dominant allele had an overall higher expression than the recessive allele across development and internode position, while both alleles' expressions peaked at 46 days after planting and progressively decreased from the top to lower internodes. The orthologue of qHT7.1 was identified to underlie the brachytic1 (br1) locus in maize. A large insertion in exon 3 and a 160 bp insertion at the promoter region were identified in the br1 mutant, while an 18 bp promoter insertion was found to be associated with reduced plant height in a natural recessive allele. CRISPR/Cas9-induced gene knockout of br1 in two maize inbred lines showed significant plant height reduction. These findings revealed functional connections across natural, mutant, and edited alleles of this MYB transcription factor in sorghum and maize. This enriched our understanding of plant height regulation and enhanced our toolbox for fine-tuning plant height for crop improvement.

The rate of sucrose export from leaves is a major factor in balancing whole-plant carbon and energy partitioning. A comprehensive study of its dynamics and relationship to photosynthesis, sink demand, and other relevant processes is hampered by the shortcomings of current methods for measuring sucrose phloem loading. We utilize the ability of sucrose transporter proteins, known as SUCs or SUTs, to specifically transport the fluorescent molecule esculin in a novel assay to measure phloem loading rates. Esculin was administered to source leaves and its fluorescence in the leaf extract was measured after 1 or 2 h. Dicot plants with an active phloem loading strategy showed an export-dependent reduction of esculin fluorescence. Relative leaf esculin export rates correlated with leaf export rates of isotopic carbon and phloem exudate sucrose levels. We used esculin experiments to examine the effects of phytohormones on phloem loading in Arabidopsis, showing, for example, that auxin induces phloem loading while cytokinin reduces it. Transcriptional regulation of AtSUC2 by AUXIN RESPONSE FACTOR1 (ARF1) corroborated the link between auxin signaling and phloem loading. Unlike established methods, the esculin assay is rapid and does not require specialized equipment. Potential applications and limitations of the esculin assay are discussed.

The tea plant (Camellia sinensis) is a perennial green plant, and its tender leaves are rich in secondary metabolites, such as theanine. Ethylamine (EA), a small amine, is an important prerequisite for theanine synthesis. However, beyond its involvement in theanine synthesis, the other physiological functions of EA in tea plants remain unknown. In vitro experiments indicate that EA may function as scavengers of reactive oxygen species (ROS) to protect the plant against damage caused by osmotic stress. Additionally, a significant correlation between EA levels and osmotic tolerance has been observed in different tea varieties. From the results, alanine decarboxylase (CsAlaDC)-silenced tea leaves and overexpressed CsAlaDC Arabidopsis thaliana lines decreased and increased EA levels, respectively, and mediated ROS homeostasis, thus exhibiting a sensitive and tolerant phenotype. In addition, the transcription factor (TF) CsCBF4 was functionally identified, which can directly bind to the CsAlaDC promoter. CsCBF4-silenced tea leaves significantly reduced the expression levels of CsAlaDC and in turn EA content, resulting in excess ROS accumulation and an osmotic-sensitive phenotype. Taken together, these results established a new regulatory module consisting of CBF4-CsAlaDC responsible for EA accumulation and ROS homeostasis in response to osmotic stress.