De novo domestication in the Solanaceae: advances and challenges.

The advent of highly efficient genome editing (GE) tools, coupled with high-throughput genome sequencing, has paved the way for the accelerated domestication of crop wild relatives. New crops could thus be rapidly created that are well adapted to cope with drought, flooding, soil salinity, or insect damage. De novo domestication avoids the complexity of transferring polygenic stress resistance from wild species to crops. Instead, new crops can be created by manipulating major genes in stress-resistant wild species. However, the genetic basis of certain relevant domestication-related traits often involve epistasis and pleiotropy. Furthermore, pan-genome analyses show that structural variation driving gene expression changes has been selected during domestication. A growing body of work suggests that the Solanaceae family, which includes crop species such as tomatoes, potatoes, eggplants, peppers, and tobacco, is a suitable model group to dissect these phenomena and operate changes in wild relatives to improve agronomic traits rapidly with GE. We briefly discuss the prospects of this exciting novel field in the interface between fundamental and applied plant biology and its potential impact in the coming years.

Physiological and metabolic changes in response to Boron levels are mediated by ethylene affecting tomato fruit yield.

Boron (B) is an essential nutrient for the plant, and its stress (both deficiency and toxicity) are major problems that affect crop production. Ethylene metabolism (both signaling and production) is important to plants' differently responding to nutrient availability. To better understand the connections between B and ethylene, here we investigate the function of ethylene in the responses of tomato (Solanum lycopersicum) plants to B stress (deficiency, 0 µM and toxicity, 640 µM), using ethylene related mutants, namely nonripening (nor), ripening-inhibitor (rin), never ripe (Nr), and epinastic (Epi). Our results show that B stress does not necessarily inhibit plant growth, but both B stress and ethylene signaling severely affected physiological parameters, such as photosynthesis, stomatal conductance, and chlorophyll a fluorescence. Under B toxicity, visible symptoms of toxicity appeared in the roots and margins of the older leaves through necrosis, caused by the accumulation of B which stimulated ethylene biosynthesis in the shoots. Both nor and rin (ethylene signaling) mutants presented similar responses, being these genotypes more sensitive and displaying several morphophysiological alterations, including fruit productivity reductions, in response to the B toxicity conditions. Therefore, our results suggest that physiological and metabolic changes in response to B fluctuations are likely mediated by ethylene signaling.

How diverse a genus can be: An integrated multi-layered analysis into Desmonostoc (Nostocaceae, Cyanobacteriota).

Cyanobacteria (Phylum Cyanobacteriota) are Gram-negative bacteria capable of performing oxygenic photosynthesis. Although the taxonomic classification of cyanobacteria was for a long time based primarily on morphological characters, the application of other techniques (e.g. molecular phylogeny), especially in recent decades, has contributed to a better resolution of cyanobacteria systematics, leading to a revision of the phylum. Although Desmonostoc occurs as a new genus/cluster and some species have been described recently, relatively few studies have been carried out to elucidate its diversity, which encompasses strains from different ecological origins, or examine the application of new characterization tools. In this context, the present study investigated the diversity within Desmonostoc, based on morphological, molecular, metabolic, and physiological characteristics. Although the usage of physiological parameters is unusual for a polyphasic approach, they were efficient in the characterization performed here. The phylogenetic analysis based on 16S rRNA gene sequences put all studied strains (25) into the D1 cluster and indicated the emergence of novel sub-clusters. It was also possible to observe that nifD and nifH exhibited different evolutionary histories within the Desmonostoc strains. Collectively, metabolic and physiological data, coupled with the morphometric data, were in general, in good agreement with the separation based on the phylogeny of the 16S rRNA gene. Furthermore, the study provided important information on the diversity of Desmonostoc strains collected from different Brazilian biomes by revealing that they were cosmopolitan strains, acclimatized to low luminous intensities, with a large metabolic diversity and great biotechnological potential.

Bioaccumulation and physiological traits qualify Pistia stratiotes as a suitable species for phytoremediation and bioindication of iron-contaminated water.

Serious concerns have recently been raised regarding the association of Fe excess with neurodegenerative diseases in mammals and nutritional and oxidative disorders in plants. Therefore, the current study aimed to understand the physiological changes induced by Fe excess in Pistia stratiotes, a species often employed in phytoremediation studies. P. stratiotes were subjected to five concentrations of Fe: 0.038 (control), 1.0, 3.0, 5.0 and 7.0 mM. Visual symptoms of Fe-toxicity such as bronzing of leaf edges in 5.0 and 7.0 mM-grown plants were observed after 5 days. Nevertheless, no major changes were observed in photosynthesis-related parameters at this time-point. In contrast, plants growing for 10 days in high Fe concentrations showed decreased chlorophyll concentrations and lower net CO2 assimilation rate. Notwithstanding, P. stratiotes accumulated high amounts of Fe, especially in roots (maximum of 10,000 µg g-1 DW) and displayed a robust induction of the enzymatic antioxidant system. In conclusion, we demonstrated that P. stratiotes can be applied to clean up Fe-contaminated water, as the species displays high Fe bioaccumulation, mostly in root apoplasts, and can maintain physiological processes under Fe excess. Our results further revealed that by monitoring visual symptoms, P. stratiotes could be applied for bioindication purposes.

Nanoparticles Loaded with Essential Oil from Zanthoxylum riedelianum Engl. Leaves: Characterization and Effects on Bemisia tabaci Middle-East Asia Minor 1.

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Middle-East Asia Minor 1 is a major pest of agricultural production systems. It is controlled by synthetic insecticides. Essential oils are promising eco-friendly alternatives. This study developed and characterized nanoparticles loaded with essential oils of Zanthoxylum riedelianum Engl. (Rutaceae) leaves and evaluated their potential for B. tabaci management. The essential oil exhibited an average yield of 0.02% (w w-1) and showed as major components γ-elemene (24.81%), phytol (18.16%), bicyclogermacrene (16.18%), cis-nerolidol (8.26%), and D-germacrene (6.52%). Characterization of the nanoparticles showed a pH between 4.5 and 6.7, a zeta potential of approximately - 25 mV, particle-size distribution ranging from 450 to 550 nm, and encapsulation efficiency close to 98%. The nanoencapsulation was an efficient process that provided photostability against photodegradation. Bioassays with crude and nanoencapsulated essential oils significantly reduced the number of nymphs and eggs of B. tabaci, with the best results observed at concentrations of 5 and 2% (v v-1). Our results demonstrated that essential oils from Z. riedelianum can be nanoformulated resulting in a stable product while maintaining their biological activity against B. tabaci Middle-East Asia Minor 1.

Cell death and changes in primary metabolism: the onset of defence in Eucalyptus in the war against Leptocybe invasa.

BACKGROUND: Here, we investigated changes in primary metabolism and cell death around oviposition sites in two hybrid clones of Eucalyptus with different degrees of resistance to Leptocybe invasa Fisher & La Salle (Hymenoptera: Eulophidae), as well as tolerance to water deficiency. RESULTS: We showed that apices of the resistant clone with oviposition had a higher content of amino acids, organic acids and the compound putrescine compared with those of the susceptible clone with oviposition. By contrast, apices of the resistant clone with oviposition had lower sugar and pyruvate organic acid content than those of the susceptible clone with oviposition. Small areas of necrosis were induced around the oviposition sites in the stem apices of Eucalyptus 24 h after infestation. The resistant clone developed larger necrotic areas that showed progressive increases 24-72 h after infestation compared with the susceptible clone, in which cell death was significantly lower and no changes were observed in necrotic area over time. Thus, the programmed death of cells around the egg, modulated by several amino acids, is likely the first defence response of Eucalyptus against L. invasa. CONCLUSION: Our results serve as the basis for the early identification of key metabolites produced in plants in defence against galling insects. © 2022 Society of Chemical Industry.

Deciphering the major metabolic pathways associated with aluminum tolerance in popcorn roots using label-free quantitative proteomics.

MAIN CONCLUSION: Al responsive proteins are associated with starch, sucrose, and other carbohydrate metabolic pathways. Sucrose synthase is a candidate to Al tolerance. Al responses are regulated at transcriptional and post-transcriptional levels. Aluminum toxicity is one of the important abiotic stresses that affects worldwide crop production. The soluble form of aluminum (Al3+) inhibits root growth by altering water and nutrient uptake, a process that also reduces plant growth and development. Under long-term Al3+ exposure, plants can activate several tolerance mechanisms. To date, no reports of large-scale proteomic data concerning maize responses to this ion have been published. To investigate the post-transcriptional regulation in response to Al toxicity, we performed label-free quantitative proteomics for comparative analysis of two Al-contrasting popcorn inbred lines and an Al-tolerant commercial hybrid during 72 h under Al-stress conditions. A total of 489 differentially accumulated proteins (DAPs) were identified in the Al-sensitive inbred line, 491 in the Al-tolerant inbred line, and 277 in the commercial hybrid. Among them, 120 DAPs were co-expressed in both Al tolerant genotypes. Bioinformatics analysis indicated that starch, sucrose, and other components of carbohydrate metabolism and glycolysis/gluconeogenesis are the biochemical processes regulated in response to Al toxicity. Sucrose synthase accumulation and an increase in sucrose content and starch degradation suggest that these components may enhance popcorn tolerance to Al stress. The accumulation of citrate synthase suggests a key role for this enzyme in the detoxification process in the Al-tolerant inbred line. The integration of transcriptomic and proteomic data indicates that the Al tolerance response presents a complex regulatory network into the transcription and translation dynamics of popcorn root development.

Deciphering ploidal levels of Lippia alba by using proteomics.

Lippia alba (Mill.) N.E. Brown (Verbenaceae), popularly known as "lemon balm" or "bushy matgrass", is widely used in folk medicine due to its anti-inflammatory, antispasmodic, analgesic, and digestive properties. It was described as an autopolyploid complex with five cytotypes (2n = 30, 38, 45, 60 and 90). To enhance our understanding of the biological variation of the species, we investigated, comparatively, the proteomic profile of all ploidal levels (diploid, aneuploid, triploid, tetraploid, and hexaploid). Leaf proteins were extracted with subsequent separation by two-dimensional electrophoresis, spot analysis, and protein identification by mass spectrometry. By comparing the proteomic profile of diploid accession to the profile of the other ploidal levels we identified differential expression between the analysed spots. We identified 34 proteins with differential expression between the ploidal levels in comparison with the diploid. The identified proteins seem to play relevant roles in the primary metabolism of L. alba suggesting that a specific set of proteins was selected during the polyploidization process, being the triploid the most different one. Given that protein composition can substantially affect the desired therapeutic effect, we posit that further combination of proteomic and metabolomic studies may help to unravel genetic variations and phenotypic profiles in L. alba.

Exogenous ethylene reduces growth via alterations in central metabolism and cell wall composition in tomato (Solanum lycopersicum).

Ethylene is a gaseous hormone with a well-established role in the regulation of plant growth and development. However, its role in the modulation of carbon assimilation and central metabolism remains unclear. Here, we investigated the morphophysiological and biochemical responses of tomato plants (Solanum lycopersicum) following the application of ethylene in the form of ethephon (CEPA - 2-chloroethylphosphonic acid), forcing the classical triple response phenotype. CEPA-treated plants were characterized by growth inhibition, as revealed by significant reductions in both shoot and root dry weights, coupled with a reduced number of leaves and lower specific leaf area. Growth inhibition was associated with a reduction in carbon assimilation due to both lower photosynthesis rates and stomatal conductance, coupled with impairments in carbohydrate turnover. Furthermore, exogenous ethylene led to the accumulation of cell wall compounds (i.e., cellulose and lignin) and phenolics, indicating that exposure to exogenous ethylene also led to changes in specialized metabolism. Collectively, our findings demonstrate that exogenous ethylene disrupts plant growth and leaf structure by affecting both central and specialized metabolism, especially that involved in carbohydrate turnover and cell wall biosynthesis, ultimately leading to metabolic responses that mimic stress situations.

New Insights Into the Evolution of C4 Photosynthesis Offered by the Tarenaya Cluster of Cleomaceae.

Cleomaceae is closely related to Brassicaceae and includes C3, C3-C4, and C4 species. Thus, this family represents an interesting system for studying the evolution of the carbon concentrating mechanism. However, inadequate genetic information on Cleomaceae limits their research applications. Here, we characterized 22 Cleomaceae accessions [3 genera (Cleoserrata, Gynandropsis, and Tarenaya) and 11 species] in terms of genome size; molecular phylogeny; as well as anatomical, biochemical, and photosynthetic traits. We clustered the species into seven groups based on genome size. Interestingly, despite clear differences in genome size (2C, ranging from 0.55 to 1.3 pg) in Tarenaya spp., this variation was not consistent with phylogenetic grouping based on the internal transcribed spacer (ITS) marker, suggesting the occurrence of multiple polyploidy events within this genus. Moreover, only G. gynandra, which possesses a large nuclear genome, exhibited the C4 metabolism. Among the C3-like species, we observed intra- and interspecific variation in nuclear genome size as well as in biochemical, physiological, and anatomical traits. Furthermore, the C3-like species had increased venation density and bundle sheath cell size, compared to C4 species, which likely predisposed the former lineages to C4 photosynthesis. Accordingly, our findings demonstrate the potential of Cleomaceae, mainly members of Tarenaya, in offering novel insights into the evolution of C4 photosynthesis.

Differential development times of galls induced by Leptocybe invasa (Hymenoptera: Eulophidae) reveal differences in susceptibility between two Eucalyptus clones.

BACKGROUND: The significance of morphological responses of hosts on susceptibility against gall-inducing insects is relatively unknown, especially in planted forests. Here, we investigate the temporal morphological responses (gall development) induced by the invasive gall wasp Leptocybe invasa and the subsequent insect development in two Eucalyptus clones. RESULTS: Our results identified a novel stage of gall development, not previously reported, termed here 'brownish ring'. In both hosts similar gall development stages were observed. Although L. invasa oviposited in both clones, comparison of external morphological traits of galls over time revealed a differential response in the number of galls between clones. Comparison of the developmental time of each gall and insect stage between clones suggests that plant defense mechanisms against L. invasa are activated shortly after oviposition by the wasp, yet before gall formation. CONCLUSION: Gall number is an important parameter that should be used to measure host susceptibility among Eucalyptus clones. To the best of our knowledge, this is the first study showing differential morphological responses induced by a galling insect, even before gall formation, revealing differences in susceptibility between different plant hosts. These findings provide insight into the use of early stages of gall formation by L. invasa to prevent invasion and establishment of this pest.

Physiological and metabolic bases of increased growth in the tomato ethylene-insensitive mutant Never ripe: extending ethylene signaling functions.

KEY MESSAGE: The tomato mutant Never ripe (Nr), a loss-of-function for the ethylene receptor SlETR3, shows enhanced growth, associated with increased carbon assimilation and a rewiring of the central metabolism. Compelling evidence has demonstrated the importance of ethylene during tomato fruit development, yet its role on leaf central metabolism and plant growth remains elusive. Here, we performed a detailed characterization of Never ripe (Nr) tomato, a loss-of-function mutant for the ethylene receptor SlETR3, known for its fruits which never ripe. However, besides fruits, the Nr gene is also constitutively expressed in vegetative tissues. Nr mutant showed a growth enhancement during both the vegetative and reproductive stage, without an earlier onset of leaf senescence, with Nr plants exhibiting a higher number of leaves and an increased dry weight of leaves, stems, roots, and fruits. At metabolic level, Nr also plays a significant role with the mutant showing changes in carbon assimilation, carbohydrates turnover, and an exquisite reprogramming of a large number of metabolite levels. Notably, the expression of genes related to ethylene signaling and biosynthesis are not altered in Nr. We assess our results in the context of those previously published for tomato fruits and of current models of ethylene signal transduction, and conclude that ethylene insensitivity mediated by Nr impacts the whole central metabolism at vegetative stage, leading to increased growth rates.

Physiological and thylakoid ultrastructural changes in cyanobacteria in response to toxic manganese concentrations.

In this study, two cyanobacterial strains (morphologically identified as Microcystis novacekii BA005 and Nostoc paludosum BA033) were exposed to different Mn concentrations: 7.0, 10.5, 15.7, 23.6 and 35.4 mg L-1 for BA005; and 15.0, 22.5, 33.7, 50.6, and 76.0 mg L-1 for BA033. Manganese toxicity was assessed by growth rate inhibition (EC50), chlorophyll a content, quantification of Mn accumulation in biomass and monitoring morphological and ultrastructural effects. The Mn EC50 values were 16 mg L-1 for BA005 and 39 mg L-1 for BA033, respectively. Reduction of chlorophyll a contents and ultrastructural changes were observed in cells exposed to Mn concentrations greater than 23.6 and 33.7 mg L-1 for BA005 and BA033. Damage to intrathylakoid spaces, increased amounts of polyphosphate granules and an increased number of carboxysomes were observed in both strains. In the context of the potential application of these strains in bioremediation approaches, BA005 was able to remove Mn almost completely from aqueous medium after 96 h exposure to an initial concentration of 10.5 mg L-1, and BA033 was capable of removing 38% when exposed to initial Mn concentration of 22.5 mg L-1. Our data shed light on how these cyanobacterial strains respond to Mn stress, as well as supporting their utility as organisms for monitoring Mn toxicity in industrial wastes and potential bioremediation application.

Selenium downregulates auxin and ethylene biosynthesis in rice seedlings to modify primary metabolism and root architecture.

MAIN CONCLUSION: Selenium modulates the formation of primary and lateral roots through alterations in auxin and ethylene, leading to new patterns of root architecture in rice seedlings. Selenium (Se) at low concentrations can control root growth through interaction with hormone biosynthesis. Auxin and ethylene have been shown to control the root architecture, with most of the information obtained from the eudicots such Arabidopsis and Nicotiana tabacum. Here, we presented the effects of Se on auxin and ethylene pathways and examined their impact on primary metabolism and root system architecture in rice (Oryza sativa L.) seedlings. Se treatment increased elongation of primary root, but decreased the number and length of lateral roots. Se led to decreased expression of genes associated with the biosynthesis of auxin and ethylene, concomitantly with reduced production of these hormones by the roots. Moreover, Se decreased the abundance of transcripts encoding auxin transport proteins. Indole-3-acetic acid (IAA) treatment overrode the repressive effect of Se on lateral root growth. The ethylene synthesis inhibitor L-α-(2-aminoethoxyvinyl)-glycine (AVG) increased elongation of primary root, whereas the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) resulted in the opposite effect. Soluble sugars accumulate in roots of rice seedlings under Se treatment. Thus, Se modulates the formation of primary and lateral roots through alterations in auxin and ethylene, leading to new patterns of root architecture in rice seedlings.

On the role of the plant mitochondrial thioredoxin system during abiotic stress.

Thiol-disulfide redox exchanges are widely distributed modifications of great importance for metabolic regulation in living cells. In general, the formation of disulfide bonds is controlled by thioredoxins (TRXs), ubiquitous proteins with two redox-active cysteine residues separated by a pair of amino acids. While the function of plastidial TRXs has been extensively studied, the role of the mitochondrial TRX system is much less well understood. Recent studies have demonstrated that the mitochondrial TRXs are required for the proper functioning of the major metabolic pathways, including stomatal function and antioxidant metabolism under sub-optimal conditions including drought and salinity. Furthermore, inactivation of mitochondrial TRX system leads to metabolite adjustments of both primary and secondary metabolism following drought episodes in arabidopsis, and makes the plants more resistant to salt stress. Here we discuss the implications of these findings, which clearly open up several research avenues to achieve a full understanding of the redox control of metabolism under environmental constraining conditions.

Downregulation of mitochondrial alternative oxidase affects chloroplast function, redox status and stress response in a marine diatom.

Diatom dominance in contemporary aquatic environments indicates that they have developed unique and effective mechanisms to cope with the rapid and considerable fluctuations that characterize these environments. In view of their evolutionary history from a secondary endosymbiosis, inter-organellar regulation of biochemical activities may be of particular relevance. Diatom mitochondrial alternative oxidase (AOX) is believed to play a significant role in supplying chloroplasts with ATP produced in the mitochondria. Using the model diatom Phaeodactylum tricornutum we generated AOX knockdown lines, and followed sensitivity to stressors, photosynthesis and transcriptome and metabolome profiles of wild-type and knockdown lines. We show here that expression of the AOX gene is upregulated by various stresses including H2 O2 , heat, high light illumination, and iron or nitrogen limitation. AOX knockdown results in hypersensitivity to stress. Knockdown lines also show significantly reduced photosynthetic rates and their chloroplasts are more oxidized. Comparisons of transcriptome and metabolome profiles suggest a strong impact of AOX activity on gene expression, which is carried through to the level of the metabolome. Our data provide evidence for the involvement of mitochondrial AOX in processes central to the cell biology of diatoms, revealing that cross-talk between mitochondria and chloroplasts is crucial for maintaining sensitivity to changing environments.

Data-Mining Bioinformatics: Connecting Adenylate Transport and Metabolic Responses to Stress.

Adenine nucleotides are essential in countless processes within the cellular metabolism. In plants, ATP is mainly produced in chloroplasts and mitochondria through photophosphorylation and oxidative phosphorylation, respectively. Thus, efficient adenylate transport systems are required for intracellular energy partitioning between the cell organelles. Adenylate carriers present in different subcellular compartments have been previously identified and biochemically characterized in plants. Here, by using data-mining bioinformatics tools, we propose how, and to what extent, these carriers integrate energy metabolism within a plant cell under different environmental conditions. We demonstrate that the expression pattern of the corresponding genes is variable under different environmental conditions, suggesting that specific adenylate carriers have distinct and nonredundant functions in plants.

Cardiac risk and MCNP/SISCODES doses in RT of the left internal mammary chain with photon and electron portals.

AIM: The present study evaluated the increment of cardiac risk (CR) and absorbed dose in radiotherapy of the internal mammary chain (IMC), in particular with photon portals of 4 6 MV, and cobalt therapy (Co60); and, electron portals of 8, 12 and 16 MeV applied in the left breast, considering the adoption of a combined photon (16 Gy) and electron (30 Gy) protocols. MATERIALS AND METHODS: The modified ICRP-reference female model of 60 kg, 163 cm and 43 years of age, coil RCP-AF, was modelled. The MCNP6/SICODES codes were employed, where the spatial dose distributions and dose-volume histograms were generated. Toxicity limits and a CR model were considered. RESULTS: CR associated with the 6 MV, 4 MV and Co60 portals increased 41.1; 40.6 and 34.5%, respectively; while, in 8, 12 and 16 MeV portals, they were 5.0, 32.5 and 49.2%, respectively. High anomalous scatter radiation from electron portals was found in the left lung providing an average dose of 3.3-5.0 Gy. CONCLUSIONS: To RCP-AF, the Co60 portal for IMC-RT presented more attractive dose distribution, whose 16 Gy for photon-component produced less CR increase, 5% lower than the other photon portals. Considering electron portals, the smallest CR increase was produced by 8 MeV portal while 12-16 MeV made the risk higher. There is a call for a less hardened energetic spectrum in order to reduce CR; however, holding suitable IMC penetration. A combined Co60/8-12 MeV may bring benefits, reducing CR. The lowest risk was found to 46 Gy electron portals exclusively.

Extending the ecological distribution of Desmonostoc genus: proposal of Desmonostoc salinum sp. nov., a novel Cyanobacteria from a saline-alkaline lake.

Cyanobacteria is an ancient phylum of oxygenic photosynthetic microorganisms found in almost all environments of Earth. In recent years, the taxonomic placement of some cyanobacterial strains, including those belonging to the genus Nostocsensu lato, have been reevaluated by means of a polyphasic approach. Thus, 16S rRNA gene phylogeny and 16S-23S internal transcribed spacer (ITS) secondary structures coupled with morphological, ecological and physiological data are considered powerful tools for a better taxonomic and systematics resolution, leading to the description of novel genera and species. Additionally, underexplored and harsh environments, such as saline-alkaline lakes, have received special attention given they can be a source of novel cyanobacterial taxa. Here, a filamentous heterocytous strain, Nostocaceae CCM-UFV059, isolated from Laguna Amarga, Chile, was characterized applying the polyphasic approach; its fatty acid profile and physiological responses to salt (NaCl) were also determined. Morphologically, this strain was related to morphotypes of the Nostocsensu lato group, being phylogenetically placed into the typical cluster of the genus Desmonostoc. CCM-UFV059 showed identity of the 16S rRNA gene as well as 16S-23S secondary structures that did not match those from known described species of the genus Desmonostoc, as well as distinct ecological and physiological traits. Taken together, these data allowed the description of the first strain of a member of the genus Desmonostoc from a saline-alkaline lake, named Desmonostoc salinum sp. nov., under the provisions of the International Code of Nomenclature for algae, fungi and plants. This finding extends the ecological coverage of the genus Desmonostoc, contributing to a better understanding of cyanobacterial diversity and systematics.

Discriminating the Function(s) of Guard Cell ALMT Channels.

It has been demonstrated that ALMT (ALUMINUM-ACTIVATED MALATE TRANSPORTER) channels are important players during stomatal movements. Previous investigations on ALMT family members indicated possible redundancy at the guard cell tonoplast; however, compelling evidence has recently suggested regulatory mechanisms and individual roles for specific ALMT proteins in response to diverse environmental stimuli.