Why did England change its law on deceased organ donation in 2019? The dynamic interplay between evidence and values.

In the three years since the law on adult deceased organ donation consent in England changed to include an opt-out system, there has been no discernible change to donation rates. The lack of a positive impact on donation rates was predicted by many of those who took part in debates before and during the passage of the Bill through Parliament. This invites the question as to why England moved to an opt-out system for organ donation despite equivocal evidence of likely benefit and opposition from expert health professional organisations. To address this question qualitative analyses of Parliamentary debates on organ donation was undertaken. This revealed a shift from a dominant position, which gave primacy to the evidence of likely effects, towards a more normative position where a deemed consent option was viewed as the 'correct thing to do' and the limited and conflicting evidence viewed in a positive light. By 2017, following Wales's move to an opt-out system, together with continued lobbying for similar changes for England by professional and patient groups, alongside sustained public popularity for organ donation, the balance of opinion had shifted towards a system where deemed consent would become the default position for most English adults.

Potential donor family behaviours, experiences and decisions following implementation of the Organ Donation (Deemed Consent) Act 2019 in England: A qualitative study.

BACKGROUND: In May 2020, England implemented "deemed consent" legislation, to make it easier for individuals to donate their organs and convey their decision when alive. Families are supposed to support the decision but can still override it if they disagree. We aimed to learn more about this changed role when families were approached about organ donation. METHODS: A qualitative study using semi-structured interviews with families, feedback from nurses, comparisons with audit data, and public involvement. We used framework analysis with a health systems perspective and utilitarian theory to explore if the law worked. FINDINGS: 103 participants were interviewed representing 83 potential donation cases. In 31/83 (37%) cases donation was fully supported, in 41/83 (49%) cases families supported retrieval of some organs, tissues and procedures, and in 11/83 (13%) cases families declined completely. Themes explaining why the law was not (yet) working included: Understanding and agreeing the family's role, confusion about deemed consent, not supporting the deceased expressed decisions, organ donation as too much of a harm, the different experiences of donation pathways, transition from end-of-life to organ donation discussions, experiences of 'consent', paperwork and processes. Families frequently questioned if their relative wanted to have a surgery rather than supporting the person who died to save lives. CONCLUSION: Families use the unique experience of their relative dying in intensive care to create alternate narratives whereby the outcome satisfies their own utility and not necessarily those of the potential donor. New public ongoing media campaigns crafted to be more supportive of organ donation as a benefit to transplant recipients could help families overcome the many difficulties they encounter at the bedside. IMPLICATIONS FOR CLINICAL PRACTICE: The soft opt-out policy has not empowered nurses to help families at their most vulnerable to increase their support for and consent to deceased organ donation.

Trends in organ donation in England, Scotland and Wales in the context of the COVID-19 pandemic and 'opt-out' legislation.

BACKGROUND: In May 2020, England implemented soft 'opt-out' or 'deemed consent' for deceased donation with the intention of raising consent rates. However, this coincided with the COVID-19 pandemic, making it difficult to assess the early impact of the law change. Wales and Scotland changed their organ donation legislation to implement soft opt-out systems in 2015 and 2021 respectively. This study provides a descriptive analysis of changes in consent and transplant rates for deceased organ donation in England, Scotland and Wales. METHODS: Logistic regression and descriptive trend analysis were employed to assess the probability of a patient who died in critical care becoming a donor, and to report consent rates using data, respectively, from the Intensive Care National Audit and Research Centre (ICNARC) in England from 1 April 2014 to 30 September 2021, and from the Potential Donor Audit for England, Scotland and Wales from April 2010 to June 2023. RESULTS: The number of eligible donors in April-June 2020 were 56.5%, 59.3% and 57.6% lower in England, Scotland and Wales relative to April-June 2019 (pre-pandemic). By April-June 2023, the number of eligible donors had recovered to 87.4%, 64.2% and 110.3%, respectively, of their levels in 2019. The consent rate in England, Scotland and Wales reduced from 68.3%, 63.0% and 63.6% in April-June 2019 to 63.2%, 60.5% and 56.3% in April-June 2023. CONCLUSIONS: While the UK organ donation system shows signs of recovery from the COVID-19 pandemic, the number of eligible potential donors and consent rates remain below their pre-pandemic levels.

Dissecting the relative contribution of ECA3 and group 8/9 cation diffusion facilitators to manganese homeostasis in Arabidopsis thaliana.

Manganese (Mn) is an essential micronutrient for plant growth but becomes toxic when present in excess. A number of Arabidopsis proteins are involved in Mn transport including ECA3, MTPs, and NRAMPs; however, their relative contributions to Mn homeostasis remain to be demonstrated. A major focus here was to clarify the importance of ECA3 in responding to Mn deficiency and toxicity using a range of mutants. We show that ECA3 localizes to the trans-Golgi and plays a major role in response to Mn deficiency with severe effects seen in eca3 nramp1 nramp2 under low Mn supply. ECA3 plays a minor role in Mn-toxicity tolerance, but only when the cis-Golgi-localized MTP11 is non-functional. We also use mutants and overexpressors to determine the relative contributions of MTP members to Mn homeostasis. The trans-Golgi-localized MTP10 plays a role in Mn-toxicity tolerance, but this is only revealed in mutants when MTP8 and MTP11 are non-functional and when overexpressed in mtp11 mutants. MTP8 and MTP10 confer greater Mn-toxicity resistance to the pmr1 yeast mutant than MTP11, and an important role for the first aspartate in the fifth transmembrane domain DxxxD motif is demonstrated. Overall, new insight into the relative influence of key transporters in Mn homeostasis is provided.

Genome-wide analysis of heavy metal ATPases (HMAs) in Poaceae species and their potential role against copper stress in Triticum aestivum.

Plants require copper for normal growth and development and have evolved an efficient system for copper management based on transport proteins such as P1B-ATPases, also known as heavy metal ATPases (HMAs). Here, we report HMAs in eleven different Poaceae species, including wheat. Furthermore, the possible role of wheat HMAs in copper stress was investigated. BlastP searches identified 27 HMAs in wheat, and phylogenetic analysis based on the Maximum Likelihood method demonstrated a separation into four distinct clades. Conserved motif analysis, domain identification, gene structure, and transmembrane helices number were also identified for wheat HMAs using computational tools. Wheat seedlings grown hydroponically were subjected to elevated copper and demonstrated toxicity symptoms with effects on fresh weight and changes in expression of selected HMAs TaHMA7, TaHMA8, and TaHMA9 were upregulated in response to elevated copper, suggesting a role in wheat copper homeostasis. Further investigations on these heavy metal pumps can provide insight into strategies for enhancing crop heavy metal tolerance in the face of heavy metal pollution.

Analysis of content and online public responses to media articles that raise awareness of the opt-out system of consent to organ donation in England.

Background: Preceded by a national media campaign, in May 2020, England switched to a soft opt-out system of organ donation which rests on the assumption that individuals meeting specific criteria have consented to organ donation unless they have expressed otherwise. We aimed to learn more about how the changes were communicated, how people responded and any discrepancies between key messages and how they were interpreted by the public. Methods: Summative content analysis of 286 stories and related reader-generated comments in leading UK online news sources (April 2019 to May 2021). Further detailed thematic analysis of 21 articles with reader-generated content, complemented by thematic content analysis coding of all 286 stories. Results: Most media coverage on both organ donation and the law change was positive, with little variation over time or between publications. The importance of organ donation, benefits of the law change, and emotive stories (often involving children) of those who had donated an organ described as "superheroes" or those who had received organs as benefiting from a "miracle" were frequently cited. In contrast, reader-generated comments were markedly more negative, for example, focusing on loss of individual freedom and lack of trust in the organ donation system. Commentators wished to be able to choose who their organs were donated to, were dismissive and blaming towards minority ethnic groups, including undermining legitimate worries about the compatibility of organ donation with religious beliefs and end of life cultural norms, understanding and acceptance of brain-stem death and systemic racism. Misinformation including use of inflammatory language was common. Conclusion: The portrayal of donors and recipients as extraordinary is unlikely to help to normalise organ donation. Undermining legitimate concerns, in particular those from ethnic minorities, can alienate and encourage harmful misinformation in underrepresented groups. The discrepancies between the tone of the articles and the readers comments suggests a lack of trust across the public, health, policy and media outlets. Easily accessible, ongoing and tailored sources are needed to mitigate misinformation and disinformation and ensure key messages are better understood and accepted in order to realise the ambitions of soft opt-out organ donation policies.

The "Cinderella sector": The challenges of promoting food and nutrition for young children in early years' settings in England.

The quality of food that children eat in early childhood has profound impacts on their future wellbeing. In England, many children eat the majority of meals in early years' settings including nurseries and childminders. We conducted 16 interviews with 18 stakeholders exploring food provision, the use of voluntary nutrition guidelines, and the effects of government support on the early years' sector. Key themes emerging from our thematic analysis included feeling insufficiently consulted, undervalued, support being unequally distributed, needing to fill multiple support roles for families, disagreement about the role and effect of voluntary nutrition standards, and being chronically underfunded.

How involved are parents in their child's early years setting's food decisions and practices?

As childhood obesity and poor nutrition rates in England continue to rise, parents and childcare practitioners have key partnership roles in ensuring young children have healthy balanced diets. Yet little is known about parents' understanding and involvement in their childcare settings' food decisions and practices, and how this might be strengthened. Semi-structured interviews were carried out with a purposive sample of 59 parents with one or more children attending early years settings in England. Framework analysis was used to explore the interviews. Epstein's model of parental partnerships was adapted as a reflective lens for the findings, and their implication for early years' policy and practice. Parents reported a lack of two-way communication on food, and of opportunities for active, meaningful engagement around food and healthy eating outside of one-to-one discussions of their child's specific needs and requirements. Some parents reported a lack of trust in the food related information provided by their childcare setting. As young children spend more time in formal childcare, it is increasingly important that trusting collaborative relationships are built between parents and childcare practitioners to ensure that children have the best start in life. This study adds to the limited literature on parental involvement in early years settings. Findings suggest that more policy work and development is needed in the early years sector, particularly in ensuring clear and accessible guidelines on food in early years settings are readily available, and that practitioners and parents have more clarity about their mutual roles and responsibilities in this.

Public attitudes to, and behaviours taken during, hot weather by vulnerable groups: results from a national survey in England.

BACKGROUND: Hot weather leads to increased illness and deaths. The Heatwave Plan for England (HWP) aims to protect the population by raising awareness of the dangers of hot weather, especially for those most vulnerable. Individuals at increased risk to the effects of heat include older adults, particularly 75+, and those with specific chronic conditions, such as diabetes, respiratory and heart conditions. The HWP recommends specific protective actions which relate to five heat-health alert levels (levels 0-4). This study examines the attitudes to hot weather of adults in England, and the protective measures taken during a heatwave. METHODS: As part of a wider evaluation of the implementation and effects of the HWP, a survey (n = 3153) and focus groups, a form of group interview facilitated by a researcher, were carried out after the June 2017 level 3 heat-health alert. Survey respondents were categorised into three groups based on their age and health status: 'vulnerable' (aged 75+), 'potentially vulnerable' (aged 18-74 in poor health) and 'not vulnerable' (rest of the adult population) to hot weather. Multivariable logistic regression models identified factors associated with these groups taking protective measures. In-person group discussion, focused on heat-health, were carried out with 25 people, mostly aged 75 + . RESULTS: Most vulnerable and potentially vulnerable adults do not consider themselves at risk of hot weather and are unaware of the effectiveness of important protective behaviours. Only one-quarter of (potentially) vulnerable adults reported changing their behaviour as a result of hearing hot weather-related health advice during the level 3 alert period. Focus group findings showed many vulnerable adults were more concerned about the effects of the sun's ultra-violet radiation on the skin than on the effects of hot temperatures on health. CONCLUSIONS: Current public health messages appear to be insufficient, given the low level of (potentially) vulnerable adults changing their behaviour during hot weather. In the context of increasingly warmer summers in England due to climate change, public health messaging needs to convince (potentially) vulnerable adults of all the risks of hot weather (not just effects of sunlight on the skin) and of the importance of heat protective measures.

Acceptability of the "Love, Sex, & Choices" HIV Prevention Intervention by Hispanic Female College Students.

INTRODUCTION: Hispanic women are affected by HIV. "Love, Sex & Choices" (LSC) is an innovative 12-episode urban soap opera video series targeting young adult Black women streamed to smartphones. This study purpose was to determine whether LSC is an acceptable HIV prevention intervention for female Hispanic college students in South Florida. METHOD: After institutional review board approval, female Hispanic college students were recruited from two campuses to watch the LSC video series and complete an online evaluation survey. RESULTS: Study participants (n =101) evaluated LSC as definitely/probably important for women (97.0%), helpful for making relationship decisions (86.2%), changing attitudes about having sex (79.2%), asking partners to use a condom (80.2%), leaving partners who won't use condoms (74.2%), handling oneself in tough situations in a relationship (79.2%), and getting an HIV test (83.2%). Participants liked/related to LSC and thought their friends would also like the series. CONCLUSIONS: Results indicated that young Hispanic women related to the video series, were likely to get HIV tested after watching the video series, found the story lines realistic, and thought their friends would like the series. The next step is to test the effectiveness of LSC to change behaviors of young Hispanic women at risk of HIV.

Increased metal tolerance and bioaccumulation of zinc and cadmium in Chlamydomonas reinhardtii expressing a AtHMA4 C-terminal domain protein.

The use of microalgal biomass for metal pollutant bioremediation might be improved by genetic engineering to modify the selectivity or capacity of metal biosorption. A plant cadmium (Cd) and zinc (Zn) transporter (AtHMA4) was used as a transgene to increase the ability of Chlamydomonas reinhardtii to tolerate 0.2 mM Cd and 0.3 mM Zn exposure. The transgenic cells showed increased accumulation and internalization of both metals compared to wild-type. AtHMA4 was expressed either as the full-length (FL) protein or just the C-terminal (CT) tail, which is known to have metal-binding sites. Similar Cd and Zn tolerance and accumulation was observed with expression of either the FL protein or CT domain, suggesting that enhanced metal tolerance was mainly due to increased metal binding rather than metal transport. The effectiveness of the transgenic cells was further examined by immobilization in calcium alginate to generate microalgal beads that could be added to a metal contaminated solution. Immobilization maintained metal tolerance, while AtHMA4-expressing cells in alginate showed a concentration-dependent increase in metal biosorption that was significantly greater than alginate beads composed of wild-type cells. This demonstrates that expressing AtHMA4 FL or CT has great potential as a strategy for bioremediation using microalgal biomass.

Graphene Oxide-Upconversion Nanoparticle Based Portable Sensors for Assessing Nutritional Deficiencies in Crops.

The development of innovative technologies to rapidly detect biomarkers associated with nutritional deficiencies in crops is highly relevant to agriculture and thus could impact the future of food security. Zinc (Zn) is an important micronutrient in plants, and deficiency leads to poor health, quality, and yield of crops. We have developed portable sensors, based on graphene oxide and upconversion nanoparticles, which could be used in the early detection of Zn deficiency in crops, sensing mRNAs encoding members of the ZIP-transporter family in crops. ZIPs are membrane transport proteins, some of which are up-regulated at the early stages of Zn deficiency, and they are part of the biological mechanism by which crops respond to nutritional deficiency. The principle of these sensors is based on the intensity of the optical output resulting from the interaction of oligonucleotide-coated upconversion nanoparticles and graphene oxide in the absence or presence of a specific oligonucleotide target. The sensors can reliably detect mRNAs in RNA extracts from plants using a smartphone camera. Our work introduces the development of accurate and highly sensitive sensors for use in the field to determine crop nutrient status and ultimately facilitate economically important nutrient management decisions.

Copper excess reduces nitrate uptake by Arabidopsis roots with specific effects on gene expression.

Nitrate uptake by plants is mediated by specific transport proteins in roots (NRTs), which are also dependent on the activity of proton pumps that energize the reaction. Nitrogen (N) metabolism in plants is sensitive to copper (Cu) toxicity conditions. To understand how Cu affects the uptake and assimilation processes, this study assesses the inhibitory effects of elevated Cu levels on the expression of genes related to N absorption, transport and assimilation in roots of Arabidopsis. Plants were grown hydroponically for 45 days, being exposed to a range of Cu concentrations in the last 72 h or alternatively exposed to 5.0 µM Cu for the last 15 days. High Cu levels decreased the uptake and accumulation of N in plants. It down-regulated the expression of genes encoding nitrate reductase (NR1), low-affinity nitrate transporters (NRT1 family) and bZIP transcription factors (TGA1 and TGA4) that regulate the expression of nitrate transporters. Cu toxicity also specifically down-regulated the plasma membrane proton pump, AHA2, whilst having little effect on AHA1 and AHA5. In contrast, there was an up-regulation of high-affinity nitrate transporters from the NRT2 family when exposed to medium level of Cu excess, but this was insufficient for restoring N absorption by roots to control levels. These results demonstrate that plants display specific responses to Cu toxicity, modulating the expression of particular genes related to nitrate uptake, such as low-affinity nitrate transporters and proton pumps.

Photosynthesis is differently regulated during and after copper-induced nutritional stress in citrus trees.

Antioxidant enzymatic responses in Citrus leaves under Cu-induced stress depends on rootstock genotypes. However, there is a lack of information about how woody plants recover growth capacity after exposure to elevated Cu and whether growth is affected by the redistribution of the metal to new vegetative parts and consequently whether photosynthesis is affected. Therefore, the biomass of plants and Cu concentrations in new leaf flushes were determined in young citrus trees grafted onto contrasting rootstocks [Swingle citrumelo (SW) and Rangpur lime (RL)]. Photosynthetic rate, chlorophyll fluorescence and antioxidant enzymatic systems were evaluated in plants previously grown in nutrient solution with Cu varying from low to high levels and with no added Cu. Both rootstocks exhibited reduced plant growth under Cu toxicity. However, trees grafted onto RL exhibited better growth recovery after Cu excess, which was dependent on the modulation of antioxidant enzyme activities in roots and leaves that maintained the integrity of the photosynthetic apparatus. In contrast, plants grafted onto SW exhibited a lower photosynthetic rate at the lowest available Cu concentration. Although the highest accumulation of Cu occurred in citrus roots, the redistribution of the nutrient to new vegetative parts was proportional to the Cu concentration in the roots.

Contribution of NtZIP1-Like to the Regulation of Zn Homeostasis.

Tobacco has frequently been suggested as a candidate plant species for use in phytoremediation of metal contaminated soil but knowledge on the regulation of its metal-homeostasis is still in the infancy. To identify new tobacco metal transport genes that are involved in Zn homeostasis a bioinformatics study using the tobacco genome information together with expression analysis was performed. Ten new tobacco metal transport genes from the ZIP, NRAMP, MTP, and MRP/ABCC families were identified with expression levels in leaves that were modified by exposure to Zn excess. Following exposure to high Zn there was upregulation of NtZIP11-like, NtNRAMP3, three isoforms of NtMTP2, three MRP/ABCC genes (NtMRP5-like, NtMRP10-like, and NtMRP14 like) and downregulation of NtZIP1-like and NtZIP4. This suggests their involvement in several processes governing the response to Zn-related stress and in the efficiency of Zn accumulation (uptake, sequestration, and redistribution). Further detailed analysis of NtZIP1-like provided evidence that it is localized at the plasma membrane and is involved in Zn but not Fe and Cd transport. NtZIP1-like is expressed in the roots and shoots, and is regulated developmentally and in a tissue-specific manner. It is highly upregulated by Zn deficiency in the leaves and the root basal region but not in the root apical zone (region of maturation and absorption containing root hairs). Thus NtZIP1-like is unlikely to be responsible for Zn uptake by the root apical region but rather in the uptake by root cells within the already mature basal zone. It is downregulated by Zn excess suggesting it is involved in a mechanism to protect the root and leaf cells from accumulating excess Zn.

Functional Analysis of NtZIP4B and Zn Status-Dependent Expression Pattern of Tobacco ZIP Genes.

Tobacco is frequently considered as a plant useful for phytoremediation of metal-contaminated soil, despite the mechanisms for regulation of uptake and accumulation being largely unknown. Here we cloned and characterized a new tobacco Zn and Cd transporter NtZIP4B from the ZIP family (ZRT-IRT-Like proteins). It complemented the Zn-uptake defective yeast mutant zrt1zrt2, and rendered the wild type DY1457 yeast more sensitive to Cd. Bioinformatic analysis and transient expression of the NtZIP4B-GFP fusion protein in tobacco leaves indicated its localization to the plasma membrane. Real-time q-PCR based analysis showed that it is expressed in all vegetative organs with the highest level in leaves. The Zn status determined transcript abundance; NtZIP4B was upregulated by Zn-deficiency and downregulated by Zn excess. At the tissue level, in roots NtZIP4B is expressed in the vasculature of the middle part of the roots and in surrounding tissues including the root epidermis; in leaves primarily in the vasculature. Bioinformatic analysis identified two copies of ZIP4 in tobacco, NtZIP4A and NtZIP4B with 97.57% homology at the amino acid level, with the same expression pattern for both, indicating a high degree of functional redundancy. Moreover, the present study provides new insights into the coordinated function of NtZIP1, NtZIP2, NtZIP4, NtZIP5, NtZIP8, NtIRT1, and NtIRT1-like in response to low-to-high Zn status. Leaves were the major site of NtZIP4, NtZIP5, and NtZIP8 expression, and roots for NtZIP1, NtZIP2, NtIRT1, and NtIRT1-like. Contrasting expression level in the apical and basal root parts indicates distinct roles in root-specific processes likely contributing to the regulation of Zn root-to-shoot translocation. In summary, new insight into the role of ZIP genes in Zn homeostasis pointing to their overlapping and complementary functions, offers opportunities for strategies to modify Zn and Cd root/shoot partition in tobacco.

OsMTP11 is localised at the Golgi and contributes to Mn tolerance.

Membrane transporters play a key role in obtaining sufficient quantities of manganese (Mn) but also in protecting against Mn toxicity. We have characterized OsMTP11, a member of the Cation Diffusion Facilitator/Metal Tolerance Protein (CDF/MTP) family of metal cation transporters in Oryza sativa. We demonstrate that OsMTP11 functions in alleviating Mn toxicity as its expression can rescue the Mn-sensitive phenotype of the Arabidopsis mtp11-3 knockout mutant. When expressed stably in Arabidopsis and transiently in rice and tobacco, it localises to the Golgi. OsMTP11 partially rescues the Mn-hypersensitivity of the pmr1 yeast mutant but only slightly alleviates the Zn sensitivity of the zrc1 cot1 yeast mutant. Overall, these results suggest that OsMTP11 predominantly functions as a Mn-transporting CDF with lower affinity for Zn. Site-directed mutagenesis studies revealed four substitutions in OsMTP11 that appear to alter its transport activity. OsMTP11 harbouring a substitution of leucine 150 to a serine fully rescued pmr1 Mn-sensitivity at all concentrations tested. The other substitutions, including those at conserved DxxxD domains, reduced complementation of pmr1 to different levels. This indicates their importance for OsMTP11 function and is a starting point for refining transporter activity/specificity.

Genome-wide analysis of wheat calcium ATPases and potential role of selected ACAs and ECAs in calcium stress.

BACKGROUND: P2- type calcium ATPases (ACAs-auto inhibited calcium ATPases and ECAs-endoplasmic reticulum calcium ATPases) belong to the P- type ATPase family of active membrane transporters and are significantly involved in maintaining accurate levels of Ca2+, Mn2+ and Zn2+ in the cytosol as well as playing a very important role in stress signaling, stomatal opening and closing and pollen tube growth. Here we report the identification and possible role of some of these ATPases from wheat. RESULTS: In this study, ACA and ECA sequences of six species (belonging to Poaceae) were retrieved from different databases and a phylogenetic tree was constructed. A high degree of evolutionary relatedness was observed among P2 sequences characterized in this study. Members of the respective groups from different plant species were observed to fall under the same clade. This pattern highlights the common ancestry of P2- type calcium ATPases. Furthermore, qRT-PCR was used to analyse the expression of selected ACAs and ECAs from Triticum aestivum (wheat) under calcium toxicity and calcium deficiency. The data indicated that expression of ECAs is enhanced under calcium stress, suggesting possible roles of these ATPases in calcium homeostasis in wheat. Similarly, the expression of ACAs was significantly different in plants grown under calcium stress as compared to plants grown under control conditions. This gives clues to the role of ACAs in signal transduction during calcium stress in wheat. CONCLUSION: Here we concluded that wheat genome consists of nine P2B and three P2A -type calcium ATPases. Moreover, gene loss events in wheat ancestors lead to the loss of a particular homoeolog of a gene in wheat. To elaborate the role of these wheat ATPases, qRT-PCR was performed. The results indicated that when plants are exposed to calcium stress, both P2A and P2B gene expression get enhanced. This further gives clues about the possible role of these ATPases in wheat in calcium management. These findings can be useful in future for genetic manipulations as well as in wheat genome annotation process.

The role of ZIP transporters and group F bZIP transcription factors in the Zn-deficiency response of wheat (Triticum aestivum).

Understanding the molecular basis of zinc (Zn) uptake and transport in staple cereal crops is critical for improving both Zn content and tolerance to low-Zn soils. This study demonstrates the importance of group F bZIP transcription factors and ZIP transporters in responses to Zn deficiency in wheat (Triticum aestivum). Seven group F TabZIP genes and 14 ZIPs with homeologs were identified in hexaploid wheat. Promoter analysis revealed the presence of Zn-deficiency-response elements (ZDREs) in a number of the ZIPs. Functional complementation of the zrt1/zrt2 yeast mutant by TaZIP3, -6, -7, -9 and -13 supported an ability to transport Zn. Group F TabZIPs contain the group-defining cysteine-histidine-rich motifs, which are the predicted binding site of Zn2+ in the Zn-deficiency response. Conservation of these motifs varied between the TabZIPs suggesting that individual TabZIPs may have specific roles in the wheat Zn-homeostatic network. Increased expression in response to low Zn levels was observed for several of the wheat ZIPs and bZIPs; this varied temporally and spatially suggesting specific functions in the response mechanism. The ability of the group F TabZIPs to bind to specific ZDREs in the promoters of TaZIPs indicates a conserved mechanism in monocots and dicots in responding to Zn deficiency. In support of this, TabZIPF1-7DL and TabZIPF4-7AL afforded a strong level of rescue to the Arabidopsis hypersensitive bzip19 bzip23 double mutant under Zn deficiency. These results provide a greater understanding of Zn-homeostatic mechanisms in wheat, demonstrating an expanded repertoire of group F bZIP transcription factors, adding to the complexity of Zn homeostasis.