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Cysteine-rich receptor-like kinases (CRKs) are evolutionarily conserved DUF26-containing receptor-like kinases (RLKs). CRKs regulate pattern-triggered immunity and effector-triggered immunity by modulating reactive oxygen species (ROS) production, Ca2+ influx, mitogen-activated protein kinase (MAPK) cascade activation, phytohormone signaling, and callose deposition. CRKs control abiotic stress response and the stress–growth balance. Future research using CRISPR, inducible systems, single-cell omics, post-translational modification analysis, and proximity-labeling proteomics will advance our understanding of plant CRKs. Cysteine-rich receptor-like kinases (CRKs) belong to a large DUF26-containing receptor-like kinase (RLK) family. They play key roles in immunity, abiotic stress response, and growth and development. How CRKs regulate diverse processes is a long-standing question. Recent studies have advanced our understanding of the molecular mechanisms underlying CRK functions in Ca2+ influx, reactive oxygen species (ROS) production, mitogen-activated protein kinase (MAPK) cascade activation, callose deposition, stomatal immunity, and programmed cell death (PCD). We review the CRK structure–function relationship with a focus on the roles of CRKs in immunity, the abiotic stress response, and the growth–stress tolerance tradeoff. We provide a critical analysis and synthesis of how CRKs control sophisticated regulatory networks that determine diverse plant phenotypic outputs. [ABSTRACT FROM AUTHOR]

Transgene expression is regulated through several steps, this study focuses on the mRNA translation step. The expression level of transgenes can be increased by 5′-untranslated region (5′UTR) sequences in certain genes which act as translational enhancers. On the other hand, translation in most mRNA species is repressed by growth, development, and stress events. There is a possibility that transgene mRNA is also repressed in these conditions, despite the use of a translational enhancer. Therefore, a consistently efficient translational enhancer is needed to develop a reliable transgene expression system. Herein we searched for mRNAs translated stably under different growth, development and environmental conditions using data sets of polysome fraction assays and microarray analysis. Correct 5′UTR sequences of candidate genes were determined by cap analysis of gene expression and we tested translational ability of the candidate 5′UTRs by reporter assays. We found the 5′UTR of cold-regulated 47 gene to be an effective translational enhancer, contributing to stable high-level expression under various conditions. [ABSTRACT FROM AUTHOR]

The GLABROUS1 enhancer-binding protein (GeBP) gene family encodes typical transcription factors containing an atypical leucine zipper motif, and plays a critical role in regulating plant growth and development, as well as multiple abiotic stresses response, but little is known about the role of GeBP transcription factors in apple. In this study, seven GeBP family members were identified in apple by genome-wide analysis, expression response analysis showed that MdGeBPs had different tissue expression patterns and were responsive to a variety of hormonal and abiotic stresses. Subsequently, MdGeBP3 was cloned and transgenic Arabidopsis and apple callus were obtained for further functional characterization. MdGeBP3 protein was localized in the nucleus, and overexpression of MdGeBP3 was more sensitive to cytokinins and less sensitive to ABA. In addition, ectopic expression of MdGeBP3 in Arabidopsis resulted in reduced drought tolerance, promoted adventitious root development and delayed flowering. Overall, these results suggest that MdGeBP3 may play an important role in regulating apple growth and development, as well as abiotic stress responses. • MdGeBP family was identified in apple for the first time. • MdGeBP3 was more sensitive to cytokinins and less sensitive to ABA. • MdGeBP3 resulted in reduced drought tolerance. • MdGeBP3 promoted adventitious root development and delayed flowering. [ABSTRACT FROM AUTHOR]

Sucrose is not only the primary photosynthetic product but also the major component translocated in the phloem of economically important plant species. Sucrose transporters or carriers (SUTs or SUCs), function as sucrose/H + symporters and play a crucial role in determining the cell-to-cell distribution of sucrose throughout the entire plant. However, whether such genes are involved in responses to abiotic stress and other biological processes is largely unknown. Here, we report that MdSUT2 in apple is a homolog of the Arabidopsis vacuolar sucrose transporter AtSUT2 . Ectopic expression of MdSUT2 in Arabidopsis decreased sucrose sensitivity in germination and seeding stage and increased sucrose transport activity. In addition, our results showed that MdSUT2 impacted on plant growth by accelerating vegetative growth and promoting early flowering in Arabidopsis . Overexpression of MdSUT2 significantly improved abiotic stress tolerance including NaCl, ABA, and mannitol in apple calli and Arabidopsis . Together, these findings provide evidence that the apple sucrose transporter MdSUT2 is involved in abiotic stress resistance and the regulation of plant growth and development. [ABSTRACT FROM AUTHOR]

Ubiquitination plays an important role in regulating plant’s development and adaptability to abiotic stress. To investigate the possible functions of a wheat monoubiquitin gene Ta-Ub2 in abiotic stress in monocot and compare it with that in dicot, we generated transgenic Brachypodium plants overexpressing Ta-Ub2 under the control of CaMV35s and stress-inducible RD29A promoters. The constitutive expression of Ta-Ub2 displayed slight growth inhibition in the growth of transgenic Brachypodium distachyon under the control conditions. However, this inhibition was minimized by expression of Ta-Ub2 under the control of stress-inducible RD29A promoter. Compared with WT, the transgenic plants preserved more water and showed higher enzymatic antioxidants under drought stress, which might be related to the change in the expression of some antioxidant genes. The expression of C-repeat binding factors transcription factor genes in the transgenic B. distachyon lines were upregulated under water stress. Salt and cold tolerances of transgenic B. distachyon were also improved. Although the phenotypic changes in the transgenic plants were different, overexpression of Ta-Ub2 improved the abiotic stress tolerance in both dicot and monocot plants. The improvement in Ta-Ub2 transgenic plants in abiotic stress tolerance might be, at least partly, through regulating the gene expression and increasing the enzymatic antioxidants. [ABSTRACT FROM AUTHOR]

Mitogen-activated protein kinase (MAPK) cascades mediate various responses in plants. As the top component, MAP3Ks deserve more attention; however, little is known about the role of MAP3Ks, especially in cotton, a worldwide economic crop. In this study, a gene encoding a putative Raf-like MAP3K, GhMAP3K40, was isolated. GhMAP3K40 expression was induced by stress and multiple signal molecules. The plants overexpressing GhMAP3K40 had an enhanced tolerance to drought and salt stress at the germination stage. However, at the seedling stage, the transgenic plants suffered more severe damage after drought, exposure to pathogens and oxidative stress. The defence-related genes and the antioxidant system were activated in transgenic palnts, suggesting that GhMAP3K40 positively regulate the defence response. The transgenic plants were less able to prevent pathogenic invasion, which was due to defects in the cell structure of the leaves. The root system of the control plants were stronger compared with the transgenic plants. These results indicated a negative role of GhMAP3K40 in growth and development and GhMAP3K40 possibly caused the defects by down-regulating the lignin biosynthesis. Overall, these results suggest that GhMAP3K40 may positively regulate defence response but cause reduced tolerance to biotic and abiotic stress by negatively regulating growth and development. [ABSTRACT FROM AUTHOR]

Phytohormones not only orchestrate intrinsic developmental programs from germination to senescence but also regulate environmental inputs through complex signalling pathways. Despite building an own signalling network, hormones mutually contribute several signalling systems, which are also essential for plant growth and development, defense, and responses to abiotic stresses. One of such important signalling cascades is G-proteins, which act as critical regulators of a wide range of fundamental cellular processes by transducing receptor signals to the intracellular environment. G proteins are composed of α, β, and γ subunits, and the molecular switching between active and inactive conformation of Gα controls the signalling cycle. The active GTP bound Gα and freed Gβγ have both independent and tightly coordinated roles in the regulation of effector molecules, thereby modulating multiple responses, including hormonal responses. Therefore, an interplay of hormones with G-proteins fine-tunes multiple biological processes of plants; however, their molecular mechanisms are largely unknown. Functional characterization of hormone biosynthesis, perception, and signalling components, as well as identification of few effector molecules of G-proteins and their interaction networks, reduces the complexity of the hormonal signalling networks related to G-proteins. In this review, we highlight a valuable insight into the mechanisms of how the G-protein signalling cascades connect with hormonal responses to regulate increased developmental flexibility as well as remarkable plasticity of plants. Unlabelled Image • G-proteins and phytohormones both contribute to plant architecture as well as stress responses. • G-proteins positively regulate cell proliferation leading to plant architecture by using growth-promoting hormonal responses. • JA and SA mediated plant immunity is moderately linked with G-protein signalling. • G-proteins along with ABA and ET play a crucial role in abiotic stress tolerance by stomatal aperture regulation. [ABSTRACT FROM AUTHOR]

• Four synthetic pathways of CH 4 were identified in plants. • CH 4 is involved in plant growth and development. • CH 4 plays an important role in plant abiotic stress response. • CH 4 may interact with other signaling molecules. • CH 4 regulates the expression of some genes. Methane (CH 4), a tetrahedral molecule, has been shown to be a signaling molecule in animals and plants. Here, the synthesis of CH 4 was introduced, and 4 pathways of CH 4 production in plants were summarized. Many studies show that CH 4 might be involved in plant growth and development, including seed germination, seedling growth, lateral rooting, adventitious rooting and postharvest freshness. CH 4 also plays an important role in plant response to abiotic stresses, such as salt stress, osmotic stress and heavy metal stress. For example, CH 4 could generally enhance the abiotic stress resistance of plants by enhancing the antioxidant defense system. In addition, CH 4 displays crosstalk with other signal molecules, including nitric oxide (NO), Hydrogen sulfide (H 2 S), Carbon monoxide (CO), calcium (Ca2+), hydrogen peroxide (H 2 O 2) and auxin. CH 4 also regulates the expression of response genes under abiotic stress and in lateral and adventitious root formation. In the future studies, more attention should be paid to the synthesis molecular mechanism of CH 4 in plants and its crosstalk with phytohormone. [ABSTRACT FROM AUTHOR]