This Perspective paper inquires why, after 20 years of extensive research into the genomics of drought resistance, there are hardly any transgenic genetically modified drought-resistant crop cultivar on the market to date. An important reason is that often, the drought stress simulations and testing methods used in genomics are at fault. Guidelines for relevant drought stress physiological methods in genomics are suggested.

Retrotransposons (RTs) are major components of most eukaryotic genomes. Molecular markers play an essential role in all aspects of genetics and genomics, and RTs represent a powerful tool compared with other molecular and morphological markers. Here, we review the utility of some PCR retrotransposon-based molecular markers, including inter-primer binding sequence (IPBS), sequence-specific amplified polymorphism (SSAP), retrotransposon-based insertion polymorphism (RBIP), inter retrotransposon amplified polymorphism (IRAP) and retrotransposon-microsatellite amplified polymorphism (REMAP).

Tropical forests play a vital role in the global carbon cycle and there is growing evidence that here, phosphorus (rather than nitrogen) may be the key nutrient limiting photosynthetic rates. In a greenhouse study of Australian tropical tree species, we found that phosphorus limitation reduced photosynthetic capacity and altered nitrogen use. The results underline the importance of phosphorus effects for future studies of tropical forest productivity.

High irrigation volumes applied to the wet part of the root system are critical to successfully implement partial root zone drying irrigation (PRI) to improve vine performance compared to regulated deficit irrigation under semiarid conditions. Physiological responses induced by PRI were due to both the placement of irrigation and the volume of water. Thresholds and optima of soil water content in wet and dry root zones were established.

Fruiting in many tree species is known to impact productivity in subsequent years. In this research we tested whether almond fruit competes with leaves for nitrogen and hypothesised how this would impact leaf carbon assimilation rates through the season. The results showed that almond cannot supply sufficient nitrogen simultaneously to fully satisfy the demands of leaves and fruits born in the same spur (principal bearing structure of almond trees).

In arid systems plants die during long drought periods and their performance may depend on their use of episodic rain events. Water from these events is often rapidly lost to evaporation but plants may draw it to deep soil layers, storing it to prevent evaporation and to allow for an efficient use. This mechanism supports longer plant survival and may be of great relevance in dry environments.

The ecophysiological behaviour of grapevine cultivars in response to drought is influenced by the soil conditions and by the plant genotype. These two components interact through a complex of hydraulic and hormonal signal exchanges occurring between roots and leaves. Our work highlights the differences in these signals observed in a near-isohydric and a near-anisohydric grapevine cultivars on two soil substrates with different textures, causing different dynamics of water deprivation during an imposed increasing water stress.

It is well known that drought is an environmental stress that negatively affects peanut growth and nodulation; however, plant recovery analyses are scarce. This study establishes a framework for analysing the response of biological nitrogen fixation and antioxidant systems in a drought–recovery cycle. Efficient and dynamic regulation of antioxidant enzymes during the cycle is crucial for the restoration of normal redox metabolism within 3 days after onset of rehydration.

Cotton genotypes resistant to debilitating spider mite infestations could be used to breed mite resistant commercial cultivars and reduce yield loss and pesticide use. We found that jasmonic acid was present at higher levels in the resistant genotype. Jasmonic acid represents a possible selection tool to dramatically speed up breeding of mite resistant cotton cultivars.

Major losses in soybean production are reported annually due to the attack of the soybean cyst nematode. Soybean roots were transformed to modify the expression of two genes involved in the defence mechanism of plants against pathogens, and their response to nematode attack was studied. The treatments conferred enhanced resistance to the cyst nematode, providing an interesting strategy to improve crop protection against pathogens.

Selection of crops under saline conditions has been notoriously difficult. Simplified platforms and stress scenarios are used too often to evaluate the salt tolerance and to extrapolate to real field conditions. We evaluated growth platforms and stress scenarios and conclude that a combined salinity + drought stress scenario and a reliable growth platform are of utmost importance in screening for salt tolerance.

The mechanism of drought tolerance may be related to a photoprotective feature in cotton plants. Mehler-peroxidation reaction, photorespiration and nitrate metabolism serve as efficient alternative sinks for excess electrons to maintain electron transport flux. They are important photoprotective mechanisms in field-grown cotton to cope with drought.

The function of AtDHyPRP1 in defence response of Arabidopsis to bacterial and fungal pathogens was determined with overexpressing and RNA interference lines. AtDHyPRP1 was localised to plasmalemma and was associated with systemic acquired resistance. As a lipid transfer protein, AtDHyPRP1 is probably involved in perception and translocation of long-distance signals derived from biotic stresses via vascular tissue or plasmodesmata.

Abiotic and biotic stresses activate long-terminal repeat retrotransposons in photosynthetic eukaryotes. In this article, we reviewed the ways that retrotransposons are activated by environmental stimuli to affect restructuring and diversification of the host genome. We recommend the use of RNA-Seq data of other plant species (e.g., Rhazya stricta) to get a deeper view of activation patterns.

The increasing climatic variability results in wheat being exposed to more frequent adversities including combined low temperature and drought/waterlogging. The physiological, proteomic and transcriptional responses of wheat plants to these combined stresses were reported. The knowledge will help comprehensively understand the climate change impacts on wheat production and help optimise water management strategy to cope with the abiotic stresses.

It has been suggested that mixed forests may be more productive than mono-specific forests, but not much is known about belowground (root) production. With an ingrowth core study in 100 plots in an old-growth forest, we show that species identity is important, whereas species diversity per se influenced only fine root turnover but not fine root production.

The effects of localised soil compaction plus nutrient availability on root system architecture (RSA) and root growth dynamics have scarcely been investigated. We investigated the impact of heterogeneous soil conditions on barley RSA, and root and shoot growth using split-root rhizotrons, and observed dynamic compensatory alterations, particularly in lateral root initiation. In loose compartments formation of lateral roots started earlier than in uniform treatments and was significantly increased in compacted compartments when only these compartments were fertilised.

ERF transcription factors are implicated in a range of biological processes. However, molecular functions of most pepper ERFs remain uncharacterised. We have shown that overexpression of a pepper CaERF5 gene in tobacco enhances resistance to a bacterial disease, likely by activation of defence genes. Our results suggest that CaERF5 acts as a positive regulator in plant defence, and that overexpression of CaERF5 can be used to enhance disease resistance in crop species.

Designing an effective phenotyping strategy requires thorough understanding of plant survival under salt stress. This study aimed at characterising rice cultivars differing in salinity tolerance based on changes in chlorophyll fluorescence characteristics, growth parameters and ion accumulation. Salinity factor index calculated from PI_ABS clearly distinguished tolerance level among the cultivars. Some new salt-tolerant cultivars were identified, which could serve as donors in breeding programme and for identification of additional QTL/genes.

Salinity is a growing problem worldwide that causes a significant reduction in crop yields. We have addressed this problem by manipulating the programmed cell death pathways in rice, resulting in enhanced salt stress tolerance. The implication is that farmers could grow rice containing such a trait in environments where salinisation of the soil exists, thereby addressing food security needs.

Conductance to CO₂ diffusion within leaves (mesophyll conductance) forms a significant and variable limitation on photosynthesis but remains poorly understood. Here, mesophyll conductance was found to vary 2-fold among wheat genotypes, and to be positively related to photosynthetic rate. These results suggest that both photosynthetic rate and water-use efficiency could be improved through breeding for higher mesophyll conductance.

Heat events are a natural summer occurrence in Australian vineyards but costly in lost production, thus, protecting vines during these events is an economically important issue. We have assessed spraying water onto vines for brief periods as a means of reducing canopy temperatures. The canopies were nearly 10°C cooler during the heat events and both yields and berry composition were improved, suggesting spraying water onto vines is an effective means of reducing impacts of high temperatures.

Since the connection between cyclins and plant development involving plant hormones is poorly understood, we characterise the SlCycA3 gene to determine the effect of A3-type cyclin gene on cell-cycle-related plant growth and its regulation mechanisms under auxin treatment. Our results showed that overexpression of the SlCycA3 gene accelerated root growth and development. Cyclin abundance may function as a regulator to control root growth in response to plant hormone treatment.

Measurement of the phloem translocation of herbicides is a challenge, especially at the initial development of compounds. B. distachyon was evaluated for potential use in phloem bioassay showing a clear evidence of xylem discontinuity. This novel bioassay provides an opportunity to determine quantitatively phloem mobility of molecules in vivo without the use of radiolabel and with a high throughput during the early stages of pesticides research.

Climate change scenarios predict an increase in extreme climatic events. In our study we tested the effects of multiple extreme events on plant performance and trait intraspecific variation, and discovered that trait intraspecific variation was not induced by extreme events. However, multiple extreme events have quantitatively and qualitatively different impacts on plant performance than single events and it is difficult to predict those impacts beforehand, which hampers predicting plant responses to a future climate.

In order to further the use of plant biomass stable isotope ratios as a proxy for environmental stressors such as drought and salinity, we must understand the long-term impact of such stressors on the isotopic composition of leaf water. Here we show with stomatal count and artificial leaves, that the lower leaf water isotopic enrichment observed in mangroves compared to freshwater plants is due their larger and lower density of stomatal pores. Our results have important implications in interpreting paleoclimate with tree ring oxygen isotope ratios, since stomatal frequency and size has varied over the ages.

The intraspecific diversity of Sangiovese and Montepulciano grapevine varieties is accentuated under early water deficit. Higher physiological and productive efficiency under non-limiting water supply noted by the near-isohydric Montepulciano compared with the near-anisohydric Sangiovese was reversed when both cultivars were subjected to a pre-veraison water deficit. Sangiovese had excellent net CO₂ exchange (NCER) recovery upon re-watering and is confirmed to be better adapted to dry/hot conditions.