Advanced molecular techniques require phenotyping of large rice populations. In this study, our aim was to identify useful indicators for reliable selection of rice genotypes for productivity in saline soil with minimal time and cost. The measure of Na⁺ exclusion (leaf Na⁺ concentration) was validated as the most reliable trait for salt tolerance, as long as the plants were grown for at least 3 weeks and moved past the osmotic-stress dominated phase. The most sensitive growth components were tiller number plant^–1 and shoot water content (water g g^–1 dry weight), and these were correlated significantly with leaf Na⁺ and injury scores.

The circadian clock is the endogenous mechanism that adjusts physiology and metabolism to time of day. Glycine-rich RNA-binding proteins, which participate in the output signal of the circadian clock in source organs, exhibit circadian oscillations that depend on developmental and temperature signals in tomato fruit. Studies on the timing of the interactions and their effects on fruit growth and metabolism provide a molecular mechanism connecting oscillators with outputs in fruits.

Plants inhabiting Mediterranean coastal areas display contrasting strategies to cope with a wide range of stresses. Also, Mediterranean areas display a high level of biodiversity. Here we explored strategies adopted by two co-occurring woody evergreens when suffering from an excess of soil salinity. Species-specific leaf life-span and drought-tolerance strategies are tightly related with salt-exclusion mechanisms, which, in turn, greatly impacts upon salt-induced metabolic adjustments.

Understanding the biochemical and molecular determinants of nitrogen nutrition in grapevine is important for the quality of production and environmental protection. The nitrate uptake mechanism was studied in this crop for the first time, focusing on the high-affinity component and the need for energy coupling, highlighting nitrate induction in grapevine. The involvement of the NRT2, NRT3 and plasma membrane H⁺-ATPase gene families in nitrate uptake by roots was evaluated.

Two key enzyme DGAT genes for lipid biosynthesis, JcDGAT1 and JcDGAT2, were cloned and characterised from the potential biodiesel plant Jatropha curcas. The functional divergence of JcDGAT1 and JcDGAT2 in lipid biosynthesis was demonstrated by comparing the oil content and fatty acid compositions in both the transgenic yeast and tobacco systems. JcDGAT2 exhibited an obvious linoleic acid substrate preference in both transgenic yeast and tobacco systems.

Grain yield is closely associated with grain number in barley, and improved spikelet survival is therefore an important trait for increasing grain yield. We identified awn primordium to tipping as the most critical subphase related to spikelet abortion, regardless of growing conditions. Spikelet survival was highly genetically controlled and an in-depth analysis of this trait is a worthwhile target for increasing yield.

Salinity is a globally increasing problem threatening agricultural production and affecting plant growth through an osmotic stress that affects root water uptake. This is a comprehensive analysis of root water uptake properties (hydraulic conductivity) in wheat (Triticum aestivum L.) in response to salinity. Salinity reduces the hydraulic conductivity of roots and appears to prevent developmental changes in root water uptake pathways from taking place as they occur in nonstressed plants.

Lateral root emergence is tightly regulated, although molecular components involved in this process are still largely unknown. This study showed that overexpression of a basic/helix-loop-helix (bHLH) transcription factor AtbHLH112 specifically suppresses lateral root emergence by decreasing the local auxin level and downregulating expression of cell-wall-remodelling (CWR) genes. Our results suggest that AtbHLH112 may represent a novel repressor of cell separation during lateral root emergence.

Drought-induced tree mortality mechanisms are yet to be fully understood. We found that co-occurring now-dead and surviving Scots pines increased their intrinsic water-use efficiency over time, although the former increased it at significantly lower rates in the previous to death period than the latter. Warmer/drier climatic conditions could increase tree mortality in the Mediterranean: our results provide a possible approach to identify vulnerable pines.

The productivity and persistence of white clover are both dependent on shoot branching, so the negative effect of P deficiency on branching has profound effects. Regulation of branching in P-limited plants was shown to be via root-supplied promoter signal rather than by inhibitory signals or P nutrition. For clover, and possibly other stoloniferous species, P-deficiency indirectly inhibits branching by down regulating root-supplied promoter signal and the strigolactone pathway plays a minor role.

Wheat yields are increasingly limited by drought events occurring at a global scale, making it of paramount importance to identify drought-tolerance mechanisms. Here we report an investigation into the basis of the exceptional drought tolerance capability exhibited by an elite breeding line (RAC875) that is being used in several international breeding programs. Our data suggests that this line owes its drought tolerance to a water-saving strategy, provided by specific root anatomical and functional features that restrict its water loss by transpiration under high evaporative demand.

High elevation plants show genetically determined adaptations and phenotypically plastic acclimations in their functional traits as a response to environmental conditions. We found that 7 of 14 studied traits that enable Andean Polylepis trees to withstand cold and dry conditions show genetically determined variation among the nine species that were studied. This suggests that these traits have been important targets of selection during the evolution of high-Andean Polylepis species.

Rapid warming in in the Arctic is causing cascading changes, many of which influence how carbon is cycled and stored. Photosynthesis and respiration, the leaf-level processes that control the capture and release of CO₂, can vary across species and under long-term warming, which is important, considering the warmer tundra of the future. The results present alterations in physiological processes and can inform predictive models of carbon cycling in this region.

Since the 1960s, processing tomato yields and agronomic water use efficiency have increased by >50%. Some tomato introgression lines differ in a small genetic region that affects determinate growth habit and the presence of leaf vein chloroplasts. This study shows that a suite of morphological and physiological traits (e.g. smaller canopies and leaf gas exchange traits) were relevant to crop improvement, and highlights the importance of trait associations to overcome potential environmental constraints.

Barriers to radial oxygen loss in the outer zones of roots are an important adaptation of many wetland plants growing in waterlogged, anaerobic soils; however, the signal(s) involved in its formation require elucidation. Organic acids, compounds produced by microorganisms in waterlogged soils, promoted root barrier formation but also had detrimental effects on root growth and tissue potassium status. Tolerance to organic acid toxicity would contribute to waterlogging tolerance in plants.

Maintenance of green leaf area is involved in yield formation and grain protein concentration. A high-throughput phenotyping method to identify stay-green and early senescence phenotypes was developed. The findings contribute to a better understanding of senescence processes.

Overexpressing genes involved in ion compartmentalisation can improve the salt and drought tolerance of plants, but the effectiveness of those homologous genes from xerophytes is not clear. The aim of this study was to improve the stress tolerance of Lotus corniculatus by expressing tonoplast Na⁺/H⁺ antiporter and H⁺-PPase from the xerophyte Zygophyllum xanthoxylum: the transgenic lines showed enhanced salt and drought tolerance. Results suggest it is feasible to use functional genes of compartmentalisation from xerophytes in genetic engineering for plant stress tolerance.

One means to adapt to rising atmospheric carbon dioxide (CO₂) is to screen crop varieties to determine which line can best convert CO₂ into more seed yield. We did this for rice, and found that although all lines responded with more seed yield as CO₂ increased, the weedy line, ‘Stg-S’ increased seed yields even at day/night temperatures up to 33/25°C. Our results suggest that including novel genes from weedy lines could help in adapting crops like rice to future climate change.

Yield loss in sorghum, as in virtually all crops, results with drought. To enhance drought tolerance, this research was done to understand water transport in sorghum plants as a mechanism to regulate water loss. Genetic variation for plant water transport properties was found and this variation corresponded to variation in plant water loss under dry-air conditions, indicating that plant breeding may be possible to incorporate into sorghum varieties low water transport properties to increase drought tolerance.

Rapid turfgrass establishment from transplanted sod is economically and aesthetically important. Anchoring of hybrid Cynodon (bermudagrass or couch) sod to underlying soil by new roots was strongly affected by transplantation date in springtime and by soil texture, but not by N-P-K fertilisation; irrigation overcame any effects of dry soil on root elongation rate. This new understanding of root growth by transplanted Cynodon sod can improve turfgrass cultural practice strategies.

Desert mosses capture and utilise moisture from brief precipitation events such as dew, fog and short-term rain showers. Syntrichia caninervis can rapidly vary the angle of leaf to the stem to gain maximum photosynthetic advantage in the shortest possible time after wetting, utilising complex microtopography of leaves and leaf hair points, anatomical structures and ultrastructure mechanisms to facilitate this process. Although small and often overlooked, desert mosses play an important role in carbon sequestration in inhospitable environments unsuitable for colonisation by vascular plants.

The cuticle of a plant has a dual role (prevention or facilitation of fungal invasion) in the process of infection. Changes in chemical composition of wax during fruit development of Pingguoli pear and their role in Alternaria alternata infection were evaluated in this study. Results showed that the infection processes of A. alternata was prevented or stimulated depending on the chemical composition of the wax. These findings may offer new light on the chemical basis for wax involvement in fungal infection.

Antioxidative mechanisms of Vaccinium corymbosum cultivars under toxic Mn²⁺ and UV-B radiation were characterised. Mn²⁺ toxicity combined with UV-B radiation had a more negative effect on growth and the performance of the photosynthetic apparatus in the cultivar Bluegold than in Brigitta. Increased activation of the antioxidative and photoprotective mechanisms was the basis for increased resistance to these stresses in Brigitta compared with Bluegold.

Plot size and type are crucial considerations in the design of plant phenotyping experiments targeting growth and yield. We surveyed studies across both well-watered and water-limited environments to demonstrate how ranking can change for grain yield across wheat genotypes depending on whether hills, rows or plots are sampled. The work confirms the potential for competition and the need for assessment in larger, bordered plots particularly where genotypes are phenotypically diverse and resources such as light, water or nutrients needed for growth are limiting.

The phytohormone jasmonic acid has important functions in development and stress responses. The aim of this work was to shed light on the role of the conversion of methyl jasmonate to jasmonic acid. Manipulation of the methyl jasmonate hydrolysing enzyme in tomato plants results in enhanced susceptibility to the necrotrophic fungus Sclerotinia sclerotiorum. However, this sensitivity is not related to the methyl jasmonate esterase activity.

Copper (Cu²⁺/Cu⁺) is an essential micronutrient for all living organisms. Both deficiency and excess can cause severe nutritional and environmental damages. In the present work we studied the regulation of gene and protein expressions of two important cuproproteins, CCS and CSD2, in soybean under environmental copper excess. The obtained results allow a better understanding of the copper homeostasis in higher plants.

Improved nitrogen (N) uptake and N use efficiency of wheat could significantly reduce N fertiliser input and N losses through leaching. Large genetic variation was found for shoot biomass and N uptake among 24 wheat genotypes. The utilisation of genotypes with high early vigour could improve the efficiency of N use for biomass production and N uptake during early growth.

To understand and predict the effects of climate change on organisms requires the disentangling of the effects of temperature and humidity (which can change with temperature). By carefully controlling air moisture as well as temperature we showed that Antarctic mosses are not affected by a wide range of temperatures, but instead respond strongly to humidity. This finding is crucial to making accurate prediction of how polar vegetation (in which mosses often dominate) will respond to current and future climate changes.

The limited availability of tools for rapidly and reliably measuring plant traits under relevant conditions has impeded progress in crop improvement. We developed and evaluated a tractor-based system that can measure traits related to the heat and drought stress tolerance of field-grown plants throughout the growing season. The system has the potential to increase the quantity and quality of field trait data, facilitating the development of high yielding stress-tolerant crops.

The soybean–rhizobia symbiotic interaction is severely affected by salt stress. We analysed the short-term salt stress effects on soybean root hair ionic homeostasis, PR gene expression and its effect on nodulation. Short exposure to salt affected root hair ionic homeostasis and PR protein gene expression, and reduced the nodule number. The addition of calcium is a common agricultural practice to reverse salt effects. We report a positive effect of calcium addition on soybean nodulation under saline conditions.

Ecosystems exposed to elevated CO₂ are often found to sequester more atmospheric carbon due to increased plant growth. We show that a heathland–grass ecosystem increases root growth when exposed to elevated CO₂. The nitrogen uptake did not increase similarly but the higher root production might lead to long-term increased N uptake on a whole-plant basis.

Shrubs in the genus Ruscus have flat, photosynthetic stems that are similar in appearance to leaves: these species are adapted to tolerate combined shade and drought. The aim of this work was to clarify the mechanisms that enable Ruscus to occupy extremely low resource understory sites. We studied 57 traits of two species, Ruscus aculeatus and R. microglossum, and considering their unique adaptations and trait values, Ruscus can serve as a model for how plants can avoid a general trade-off between shade and drought tolerance.

Despite their importance in plant nutrient redistribution, the mechanisms controlling the onset of leaf senescence are poorly understood. A reduction of leaf hydraulic conductance with age influences leaf senescence in tomato, but not in tropical and temperate trees. Although reductions of transpiration rates affected leaf longevity in tomato and one tropical tree species, hydraulic regulation of the xylem-transported compounds apparently acted as an age-dependent signal controlling leaf senescence in tomato.

Daily exposure to temperatures above an optimum, as well as heat waves, reduces plant growth, development and ultimately yield. Development of heat resistant plants may improve crop yields in hot environments. By identifying genes and gene pathways involved in the heat stress response, this research shows key areas that can be targeted to breed cotton varieties with heat tolerance to improve yields in warm and hot environments.

Drought reduces the production and yield of plants worldwide, but the mechanisms that control the variable responses of plants to water limitation is still not fully understood. Among six genotypes of Sorghum bicolor we show that the hydraulic resistance of different leaf tissues correlates with stomatal conductance at different levels of drought severity. These results help explain the variability in plant responses to drought, and reveals fundamental relationships between leaf hydraulic conductance and plant water-use strategies.

Heat stress at gametogenesis in rice causes significant reduction in spikelet fertility. Currently, there is no marker available for precise phenotyping of this trait. The inter collar distance of –8 to –9 cm between the immediate fully opened leaf and the flag leaf is an effective phenotypic marker to estimate heat stress induced damage at gametogenesis. This finding will drive breeding efforts to develop heat tolerance during gametogenesis in rice.

Loss-of-function and gain-of-function approaches were utilised to detect the physiological influence of glycerol biosynthesis during salt stress and the role of glycerol in conferring salt tolerance in Arabidopsis. Results indicate the participation of glycerol overproduction in salt tolerance in Arabidopsis. Furthermore, we hypothesise that mechanism(s) of glycerol retention/efflux in the cell are affected at 200 mM NaCl in Arabidopsis.

The mechanisms by which coconut endosperm accumulates medium chain fatty acids (≈60%) are still unknown. In this paper, an acyl- acyl carrier protein thioesterase (CocoFatB1) was isolated form coconut and heterologously expressed in transgenic tobacco. The results indicated that CocoFatB1 acts specifically on 14 : 0-ACP, 16 : 0-ACP and 18 : 0-ACP, and can increase medium chain saturated fatty acid in transgenic plants.