Functional Plant Biology
Volume 45 Number 3 2018
By 2015 genetically modified (GM) crops had been commercialised for 20 years. This technology ranks amongst the most rapidly accepted by farmers, but are there downsides to these introductions? This review considers the advantages and potential disadvantages of GM crops.
FP16444Aquaporin AtTIP5;1 as an essential target of gibberellins promotes hypocotyl cell elongation in Arabidopsis thaliana under excess boron stress
Gibberellins (GAs) promote hypocotyl elongation by controlling the expression of many genes in plants. However, only a few target genes of GAs have been identified to date. The paper provides strong evidence that tonoplast aquaporin AtTIP5;1 mediates GA-stimulated hypocotyl cell elongation under excess boron condition in Arabidopsis. The finding highlights the essential roles of vacuoles and boron in GA signalling in plants.
FP17201Modelling seasonal changes in the temperature-dependency of CO2 photosynthetic responses in two Vitis vinifera cultivars
Interspecific differences in photosynthetic attributes of Chardonnay and Merlot grapevines have been established. The cause of such differences were attributed to a higher carboxylation and regeneration capacity in the Merlot leaves, especially at high temperatures and cultivar differences were exacerbated as the season progressed. Differences in biochemical processes related to assimilation at high temperatures were measured between the cultivars, and these may relate to inherent differences in temperature tolerance between these closely related cultivars.
FP17167Co-inoculation of maize with Azospirillum brasilense and Rhizobium tropici as a strategy to mitigate salinity stress
Salinity is a major factor affecting crop production worldwide. We identified enzymatic and genetic mechanisms in maize that confer tolerance against abiotic stresses when inoculated with plant growth-promoting bacteria. Inoculation with the elite strains identified in this study, of Azospirillum brasilense (Ab-V6) and Rhizobium tropici (CIAT 899) might represent a valuable and sustainable strategy to mitigate salinity stress.
Ethylene-induced abscission of young cotton fruits is a major lint yield limiting factor in cotton crop production under stressed environments. Extreme weather events such as long-term soil waterlogging and elevated CO2 can increase fruit loss caused by ethylene production in cotton. Our study showed that the physiological and yield performance of cotton crops under future environments can potentially be improved by mitigating ethylene action.
Reproductive growth is very important for plant survival and population establishment under salinity. It remains unknown whether the reproductive process of Suaeda salsa is affected by salinity. NaCl markedly increased the reproductive growth of S. salsa by increasing flower number and fertility. Unravelling the mechanisms of plant salt tolerance will be helpful for improving agricultural production.
Global demand for agricultural product is predicted to surpass our production capacity in the near future, and enhancing plant photosynthesis may be a solution for crop yield improvement. To accelerate enhancement we need to know which target(s) should be manipulated for greatest impact, therefore, a modelling tool has been developed. The tool will be able to improve our understanding of photosynthetic manipulation impacts on crop biomass accumulation, which ultimately affects crop yield.
FP17202The LmSAP gene isolated from the halotolerant Lobularia maritima improves salt and ionic tolerance in transgenic tobacco lines
Abiotic stresses pose serious threats to growth and productivity of crop plants worldwide. We describe the isolation of a novel gene, designated LmSAP, from Lobularia maritime to exploit the potential of this halophyte as a genetic resource to improve salt and ionic tolerance in plants and, particularly, in cereals. These results show that LmSAP is a potentially useful candidate gene for engineering salt and ionic tolerance in cultivated plants.
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Sorghum synthesises the specialised metabolite dhurrin, which, when enzymatically hydrolysed releases hydrogen cyanide, which is toxic to grazing animals. We used dhurrin deficient mutants to test growth–defence trade-offs at different nitrogen fertiliser levels. Plants lacking dhurrin were slower growing as seedlings but had a growth advantage at later developmental stages, suggesting a benefit of dhurrin in early growth but a cost at later stages. To maintain global food security, crop yields must be optimised while resource input is minimised.
FP17209Linking root traits to superior phosphorus uptake and utilisation efficiency in three Fabales in the Core Cape Subregion, South Africa
Dwindling phosphate reserves and the high costs of P fertilisers drive the need to develop more P-efficient crops through enhancing P uptake. We expected that Aspalathus linearis, a cluster-root-forming species, would be better at P acquisition than other species. Polygala myrtifolia, however, developed a root system with better P uptake traits and had a higher P uptake efficiency. Therefore, other root traits besides cluster roots are important for enhancing P uptake in plants.
FP17278Dynamic analysis of the impact of free-air CO2 enrichment (FACE) on biomass and N uptake in two contrasting genotypes of rice
Elevated [CO2] increases rates of photosynthesis and crop yields, but the degree of enhancement varies among cultivars. The present study indicates that the more effective use of CO2 in IIY compared with WYJ results in a strong response in root growth, nitrogen uptake, and in yield, N synchronises biomass responses between shoot and root. Our findings help clarify key mechanisms by which elevated [CO2] elicits differential growth and yield responses among cultivars in rice.
FP17304Selection of optimal reference genes for quantitative RT-PCR transcript abundance analysis in white clover (Trifolium repens L.)
Quantitative reverse transcription PCR, a widely used technique for measuring the transcriptional activity of genes, is critically dependent upon the use of reference genes. This manuscript is the first reported systematic search for reference genes in the commercially important forage legume white clover. Three genes, out of seven evaluated, were identified as reliable references, paving the way for future work on any gene in white clover.
FP17241Structural and functional disorder in the photosynthetic apparatus of radish plants under magnesium deficiency
Detection of nutrients deficiency in plants has previously been based on either observation of visible changes or destructive estimation methods. Here we identify parameters related to photosynthetic efficiency that enable early detection of Mg deficiency in radish plants before visual symptoms appear. We confirm that some parameters can be used as bioindicators for transient and persistent Mg deficiency.
FP17127Enhancing antioxidant systems by exogenous spermine and spermidine in wheat (Triticum aestivum) seedlings exposed to salt stress
Salinity stress is one of the major limitations to crop productivity worldwide. The aim of the present study was to understand the functional role of spermidine and spermine with respect to salt stress in wheat seedlings. Our results show that exogenous spermidine and spermine effectively up-regulated transcriptional levels of antioxidant enzyme genes and improved the defence response of plants under salt stress.
FP17192MeBIK1, a novel cassava receptor-like cytoplasmic kinase, regulates PTI response of transgenic Arabidopsis
Cassava bacterial blight is the most destructive disease of cassava, which results in a significant reduction in cassva production caused by Xanthomonas axonopodis pv. manihotis; however, little is known about the resistance mechanisms of cassava bacterial blight. In our study, MeBIK1, an ortholog of the AtBIK1 gene was cloned from cassava and MeBIK1 was found to positively regulate pathogen resistance. Our results provide the basis for elucidating the mechanism of disease resistance in cassava.
FP17266Improving nitrogen use efficiency in plants: effective phenotyping in conjunction with agronomic and genetic approaches
Nitrogen use efficiency (NUE) in most crops is low, resulting in N waste, leading to increased crop production costs and environmental concerns globally. Efficient and reliable phenotyping would help manage N application and speeding up efforts to breed crop varieties with higher NUE. A comprehensive insight is provided into the approaches, tools and methods applicable to phenotyping NUE-related traits in crops.
CAM is a flexible photosynthetic mode conferring robust environmental resilience. This investigation tackles the scarcity of data linking anatomical evolution and CAM function, showing that in a diverse family, co-option and augmentation of existing succulence was integral to multiple CAM origins. The results clarify the evolution of CAM and also help define the baseline level of cell and tissue succulence required in efforts to bioengineer CAM into food and biomass crops.
FP17249S-nitrosocysteine-responsive genes modulate diverse regulatory pathways in Oryza sativa: a transcriptome profiling study
One of the good news in plants is NO news. NO is an all-around molecule that plays a vital role during the entire life cycle of plants. This study identified a large number of genes that were activated in response to exogenous NO in rice. In conclusion, NO mediates the transcriptional control of genes involved in a wide variety of physiological functions in rice.
FP17195Wheat pre-anthesis development as affected by photoperiod sensitivity genes (Ppd-1) under contrasting photoperiods
The duration of phases leading to wheat anthesis date, and hence yield potential, are regulated by daylength (photoperiod). Genes controlling the response to photoperiod (Ppd-1): (i) provided varying magnitudes of insensitivity; (ii) were not particularly associated to duration – photoperiod sensitivity – of any specific phase; and (iii) showed no additive effect when stacked. Further investigation with different allelic variants should be conducted to tailor time to anthesis and duration of each particular phase to improve wheat yield potential facing climate change.
FP17162Antioxidant capacity along the leaf blade of the C3-CAM facultative bromeliad Guzmania monostachia under water deficit conditions
Guzmania monostachia is an epiphytic, tank-forming bromeliad that displays variable degrees of crassulacean acid metabolism (CAM) along the leaf blade under water deficit conditions. The hypothesis that the most intense CAM found in the apex portion is related to reduced oxidative burden was not confirmed. However, G. monostachia was able to keep reactive oxygen species under tolerable levels under water deficit conditions by increasing the antioxidant capacity in the apex, which is the leaf portion most exposed to light.
FP17147XopR TTSS-effector regulates in planta growth, virulence of Indian strain of Xanthomonas oryzae pv. oryzae via suppressing reactive oxygen species production and cell wall-associated rice immune responses during blight induction
Bacterial pathogens secret effectors to modulate plant immunity, enabling unlimited pathogen growth inside host, and causing disease. Xanthomonas oryzae pv. oryzae executes XopR effector to suppress immune responses in rice for its growth and subsequent blight disease. This finding provides insights into understanding the key weapon used by the pathogen, and will help to identify the novel targets for disease management.
FP17199Seasonal variations of leaf chlorophyll–protein complexes in the wintergreen herbaceous plant Ajuga reptans L.
In the perennial herbaceous wintergreen plant Ajuga reptans (bugle), the photosynthetic apparatus (PSA) is reorganised during winter. The aim of this work was to examine the structural changes in the pigment–protein complexes of PSA. Changes in aggregation of the thylakoid protein complexes were observed including a restructuring of the PSI–PSII megacomplex and the PSII–LHCII supercomplex parallel to changes in the zeaxanthin-dependent protective mechanism.
FP17303Integrated genomics, physiology and breeding approaches for improving nitrogen use efficiency in potato: translating knowledge from other crops
Potato is a high nitrogen-responsive crop, hence improving nitrogen use efficiency (NUE) of plant is important to reduce production cost and minimize environmental loss. Potato is a less studied crop especially at plant level with enhanced NUE. This review highlights translation of advanced NUE research from other plants like Arabidopsis, rice, wheat and maize applying integrated genomics, physiology and breeding approaches.
Root properties impact strongly on plant performance, but high-throughput methods for non-invasive and quantitative root trait assessment are rarely available. We developed and tested a root phenotyping concept, which involves NIR imaging of roots grown along surfaces of transparent culture vessels using visible light blocking long pass filters. We reveal the viability of the concept and its suitability for simultaneous root and shoot phenotyping.
FP17226Constitutive expression of CaHSP22.5 enhances chilling tolerance in transgenic tobacco by promoting the activity of antioxidative enzymes
Chilling stress limits the productivity and geographical distribution of many plants throughout the world. Accumulation of the endoplasmic reticulum-located small heat shock protein CaHSP22.5 enhanced photochemical activity and oxidation resistance and alleviated endoplasmic reticulum stress caused by chilling stress in transgenic tobacco plants. CaHSP22.5 could be useful for improving the tolerance of chilling-sensitive plant types.
Understanding the mechanism of high-temperature stress (heat) tolerance during the plant reproductive phase is important for developing heat tolerant cultivars in lentil. We found a higher reduction in pollen viability and lower photosynthetic electron transport rate in heat sensitive genotypes and a functional marker amplified only in heat tolerant ones. We conclude that these traits and the associated functional markers will be useful in lentil breeding.
FP17288Identification of MdDof genes in apple and analysis of their response to biotic or abiotic stress
In the study presented we identified MdDof genes in apple and analysed their response to biotic/abiotic stress. The aim of the work was to give references to understand the function of MdDof genes generally and serve as a reference for studies of Dof zinc finger genes in other plants. Finally, we fit the original images into the software Photoshop 6.0 for bigger pictures.
FP17233Impact of hemlock woolly adelgid (Adelges tsugae) infestation on xylem structure and function and leaf physiology in eastern hemlock (Tsuga canadensis)
Hemlock woolly adelgid (HWA) is an invasive insect that feeds upon the foliage of eastern hemlock trees leading to a decline in health and mortality. During early infestation, HWA-induced decline in the health of eastern hemlock is not initially caused by compromised water transport or needle loss. Our results contribute to efforts to understand the mechanisms leading to the demise of eastern hemlocks.
FP17212Structural and functional characterisation of two novel durum wheat annexin genes in response to abiotic stress
Abiotic stress reduces the grain yield of cereal crops. Here, we show that the two durum wheat annexin genes, TdAnn6 and TdAnn12, are induced by different abiotic stresses and heterologous expression in yeast improves tolerance to different stresses. These results show that the two annexins are potentially useful candidate genes for engineering abiotic stress tolerance in cultivated plants.
FP17274Hydrogen sulfide may function downstream of hydrogen peroxide in mediating darkness-induced stomatal closure in Vicia faba
We proved for the first time the effects of H2S, a novel gasotransmitter, on darkness-induced stomatal closure and the relationship with H2O2 in Vicia faba. Here we found that H2S mediated darkness-induced stomatal closure in Vicia faba and it acted downstream of H2O2 in this process. This work enriches the signalling network during darkness-regulated stomatal movement and provides evidence for further research.
FP17265Biochemical and transcriptomic analysis of maize diversity to elucidate drivers of leaf carbon isotope composition
Leaf carbon isotope composition (δ13C) has been used to screen for water-use efficiency in C3 plants, but gaps in the understanding of factors influencing δ13C have limited its application in C4 species. This study exploited maize genetic diversity to explore biochemical and post-photosynthetic factors that may influence δ13C. Our findings indicate that the observed variation in leaf carbon isotope composition across diverse maize lines is likely driven by differences in stomatal and mesophyll conductance and not photosynthetic or respiratory metabolism.
Sustaining plant productivity under microgravity conditions is a prerequisite for successful colonisation of space by humans. Therefore, we address the effects of simulated microgravity on seed germination and the first steps of seedling development at the total proteome level. This study complements a large body of transcriptomic data and gives an insight into gravity-related changes in early plant ontogenesis.
FP17180The regulator of G-protein signalling protein mediates D-glucose-induced stomatal closure via triggering hydrogen peroxide and nitric oxide production in Arabidopsis
Stomatal guard cells sense and respond to sugar, but the means by which they do so have not been fully elucidated. Our study showed that RGS1, a putative receptor for D-glucose, mediates D-glucose-induced H2O2 and NO production in guard cells and subsequent stomatal closure. The data suggest that photosynthetic product D-glucose, as an integrative signal, coordinates plant CO2 uptake with water loss.
FP16393Role of the antioxidant system in the regulation of the chlorophyll biosynthesis pathway in the vascular plant Cucumis sativus
Fine tuning the flow of chlorophyll biosynthesis pathway is crucial for the growth and development of the plants. Antioxidant systems were found to influence this pathway through maintaining the specific concentration of H2O2. This finding provides insights into understanding the antioxidant-mediated regulation of chlorophyll biosynthesis in detail, and will help in the development of oxidative stress-resistant plants.
Many environmental stresses are periodic and predictable. Plants have adapted to these by temporally organising their stress responses to maximise efficiency and efficacy. We review current evidence for temporal regulation of responses to the environment and environmental impacts on the plant circadian clock. Better understanding of the reciprocal interactions between the plant circadian clock and environmental stresses may aid in identifying mechanisms to improve plant growth and increase food security.
FP17203The involvement of programmed cell death in inflated leaf petiole morphogenesis in Trapa pseudoincisa
The inflated leaf petiole of Trapa pseudoincisa undergoes a developmental process from solid to hollow phase. Schizo-lysigenous aerenchyma was developed via the mechanism of programmed cell death (PCD) during the process of inflated leaf petiole morphogenesis. Thus, a trans-disciplinary systems approach that recognizes the need for integration of cytological and molecular characteristics for identification of aerenchyma type in aquatic plant is required.
FP17095Involvement of signalling molecules NO, H2O2 and H2S in modification of plasma membrane proton pump in cucumber roots subjected to salt or low temperature stress
Cascades by which signalling molecules participate in plant responses to changes in environmental conditions are still under intensive study. Our aim was to explain the role of NO, H2O2 and H2S in adaptation of cucumber seedlings to both salt and low temperature stress. Results show that signalling molecules are important for understanding the mechanisms of modification of the activity of the plasma membrane proton pump, which is a key enzyme in abiotic stress conditions.
Chlorophyll b is the major regulator of photosynthetic antennae in land plants. Its absence diminishes light harvesting, photoprotection and ultimately photosynthesis. We show that barley mutants lacking chl b display impaired stomatal control, which can be restored by temporal shading of the plants. Thus the effects of this mutation extend beyond chloroplast metabolism.
These articles have been peer reviewed and accepted for publication. They are still in production and have not been edited, so may differ from the final published form.
Energy-crises in well-aerated and anoxic tissue: does tolerance require the same specific proteins and energy-efficient transport
Exogenous spermidine enhances the photosynthetic and antioxidant capacity of rice under heat stress during early grain-filling period
DIURNAL VARIATION IN GAS EXCHANGES AND NON-STRUCTURAL CARBOHYDRATES THROUGHOUT SUGARCANE DEVELOPMENT
Rising [CO2] changes competition relationships between native woody and alien herbaceous Cerrado species
Improved leaf nitrogen reutilization and Rubisco activation under short-term nitrogen-deficient conditions promotes photosynthesis in winter wheat (Triticum aestivum L.) at the seedling stage
Mild pre-flowering drought priming improves stress defenses, assimilation and sink strength in rice under severe terminal drought
Phosphorus deficiency alters scaling relationships between leaf gas exchange and associated traits in a wide range of contrasting Eucalyptus species
Differential protein expression reveals salt tolerance mechanism of Desmostachya bipinnata at moderate and high levels of salinity
Grapevine fanleaf virus affects grape (Vitis vinifera L.) berry anthocyanin content via the transcriptional regulation of anthocyanin biosynthetic genes
Pearl millet [Pennisetum glaucum (L.) R. Br.] contrasting for the transpiration response to vapour pressure deficit also differ in their dependence on the symplastic and apoplastic water transport pathways
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Functional Plant Biology (Online Early)Rongli Shi, Astrid Junker, Christiane Seiler, Thomas Altmann
Functional Plant Biology 45 (3)Jennifer A. Thomson
Functional Plant Biology 44 (4)Mark T. Waters
Functional Plant Biology 45 (3)Alex Wu, Al Doherty, Graham D. Farquhar, Graeme L. Hammer
Unravelling the plant signalling machinery: an update on the cellular and genetic basis of plant signal transductionFunctional Plant Biology 45 (2)Vadim Demidchik, Frans Maathuis, Olga Voitsekhovskaja
Functional Plant Biology 45 (2)Lauren A. E. Erland, Praveen K. Saxena, Susan J. Murch
Functional Plant Biology 45 (2)Anna V. Tsyganova, Anna B. Kitaeva, Viktor E. Tsyganov
The role of ion disequilibrium in induction of root cell death and autophagy by environmental stressesFunctional Plant Biology 45 (2)Vadim Demidchik, Elena V. Tyutereva, Olga V. Voitsekhovskaja
Aquaporin AtTIP5;1 as an essential target of gibberellins promotes hypocotyl cell elongation in Arabidopsis thaliana under excess boron stressFunctional Plant Biology 45 (3)Yongqi Pang, Jintong Li, Bishu Qi, Mi Tian, Lirong Sun, Xuechen Wang, Fushun Hao
Functional Plant Biology 45 (2)Shuitian Luo, Xiao Zhang, Jinfei Wang, Chunyang Jiao, Yingying Chen, Yingbai Shen
Overexpression of GSK3-like Kinase 5 (OsGSK5) in rice (Oryza sativa) enhances salinity tolerance in part via preferential carbon allocation to root starchFunctional Plant Biology 44 (7)Maysaya Thitisaksakul, Maria C. Arias, Shaoyun Dong, Diane M. Beckles
Studies of cytokinin receptor–phosphotransmitter interaction provide evidences for the initiation of cytokinin signalling in the endoplasmic reticulumFunctional Plant Biology 45 (2)Sergey N. Lomin, Yulia A. Myakushina, Dmitry V. Arkhipov, Olga G. Leonova, Vladimir I. Popenko, Thomas Schmülling, Georgy A. Romanov
Functional Plant Biology 44 (6)Barbara Beikircher, Stefan Mayr
Modelling seasonal changes in the temperature-dependency of CO2 photosynthetic responses in two Vitis vinifera cultivarsFunctional Plant Biology 45 (3)Dennis H. Greer
Antioxidant capacity along the leaf blade of the C3-CAM facultative bromeliad Guzmania monostachia under water deficit conditionsFunctional Plant Biology (Online Early)Maria E. Abreu, Victória Carvalho, Helenice Mercier
Functional Plant Biology 44 (11)Rachael H. Nolan, Kendal A. Fairweather, Tonantzin Tarin, Nadia S. Santini, James Cleverly, Ralph Faux, Derek Eamus
Integrated genomics, physiology and breeding approaches for improving nitrogen use efficiency in potato: translating knowledge from other cropsFunctional Plant Biology (Online Early)Jagesh K. Tiwari, Darren Plett, Trevor Garnett, Swarup K. Chakrabarti, Rajesh K. Singh
Myotubularins, PtdIns5P, and ROS in ABA-mediated stomatal movements in dehydrated Arabidopsis seedlingsFunctional Plant Biology 45 (2)Akanksha Nagpal, Ammar Hassan, Ivan Ndamukong, Zoya Avramova, František Baluška
Endoplasmic reticulum stress regulates glutathione metabolism and activities of glutathione related enzymes in ArabidopsisFunctional Plant Biology 45 (2)Baris Uzilday, Rengin Ozgur, A. Hediye Sekmen, Ismail Turkan
Functional Plant Biology 44 (12)Joanne Tilbrook, Rhiannon K. Schilling, Bettina Berger, Alexandre F. Garcia, Christine Trittermann, Stewart Coventry, Huwaida Rabie, Chris Brien, Martin Nguyen, Mark Tester, Stuart J. Roy