Interactional effects of climate change factors on the water status, photosynthetic rate, and metabolic regulation in peach

Environmental stress factors caused by climate change affect plant growth and crop production, and pose a growing threat to sustainable agriculture, especially for tree crops. In this context, we sought to investigate the responses to climate change of two Prunus rootstocks (GF677 and Adesoto) budded with Catherina peach cultivar. Plants were grown in 15 L pots in temperature gradient greenhouses for an 18 days acclimation period after which six treatments were applied: [CO2 levels (400 versus 700 mol mol-1), temperature (ambient versus ambient + 4°C), and water availability (well irrigated versus drought)]. After 23 days, the effects of stress were evaluated as changes in physiological and biochemical traits, including expression of relevant genes. Stem water potential decreased under drought stress in plants grafted on GF677 and Adesoto rootstocks; however, elevated CO2 and temperature affected plant water content differently in both combinations. The photosynthetic rate of plants grafted on GF677 increased under high CO2, but decreased under high temperature and drought conditions. The photosynthetic rates of plants grafted onto Adesoto were only affected by drought treatment. Furthermore, in GF677-Catherina plants, elevated CO2 alleviated the effect of drought, whereas in those grafted onto Adesoto, the same condition produced acclimation in the rate. Stomatal conductance decreased under high CO2and drought stress in both graftedrootstocks, and the combination of these conditions improved water-use efficiency.Changes in the sugar content in scion leaves and roots were significantly differentunder the stress conditions in both combinations. Meanwhile, the expression of mostof the assessed genes was significantly affected by treatment. Regarding genotypes,GF677 rootstock showed more changes at the molecular and transcriptomic level thandid Adesoto rootstock. A coordinated shift was found between the physiological statusand the transcriptomic responses. This study revealed adaptive responses to climatechange at the physiological, metabolic, and transcriptomic levels in twoPrunusrootstocks budded with 'Catherina'. Overall, these results demonstrate the resilient capacity andplasticity of these contrasting genotypes, which can be further used to combat ongoingclimate changes and support sustainable peach production

Dissimilar esponses of ancient grapevines recovered in Navarra (Spain) to arbuscular mycorrhizal symbiosis in terms of berry quality

The exploitation of genetic diversity within agricultural plants, including grapevine, is suggested as a valuable tool to cope with the negative impacts of climate change on yield and crop quality. In some winegrowing regions of Europe, there is a renewed interest in knowing the grapevine genetic resources available, focusing on the prospection, recovery, and study of ancient cultivars typical of every zone. Grapevines are naturally associated with arbuscular mycorrhizal fungi (AMF), which provide some benefits to the host plant, although such effects depending on many factors, including variety. Therefore, the aim of this research was to characterize the potential fruit quality of eight old grapevine varieties recovered in Navarre (northeastern of the Iberian Peninsula), associated or not with AMF. The study was carried out on fruit-bearing cuttings grown under controlled conditions (greenhouse). Overall, AMF inoculation reduced bunch and berry mass, as well as phenolic content in fruits. In some varieties, AMF association improved some berry traits by increasing the concentrations of soluble solids and anthocyanins; in others, berry colour, total phenolic and anthocyanin content were diminished in AMF-inoculated plants. The results, therefore, suggest that intraspecific diversity of old grapevines could include different abilities to respond to arbuscular mycorrhizal symbiosis

Improving resource productivity at a crop sequence level

The challenge to increase agricultural production with a minimum environmental impact requires to reach themaximum effiency in the capture and use of resources such as photosynthetically active radiation (PAR), water,and nitrogen (N). Such requisites are encompassed in the ecological intensifiation (EI) concept. The aims of this work were to evaluate at a crop sequence level: i) crops yields, ii) water and radiation productivity and itscomponents, i.e. resource capture and resource use effiency, and iii) partial factor productivity of applied N(PFPN), partial nutrient balance for N (PNB), N uptake and N utilization effiency of a two-year, three-cropsequence (wheat [Triticum aestivum L.]/soybean [Glycine max (L.) Merr.] double crop – maize [Zea mays L.])carried-out under EI principles in comparison with the same crop sequence under current farmer practices (FP) intwo contrasting locations of the Argentinean Pampas, i.e. Paraná (-31°50′; -60°31′) at the northern Pampas andBalcarce (-37°45′, -58°18′) at the southern Pampas. Experiments were carried-out during four consecutive years,covering two complete cycles of the crop sequence. For the accumulated grain production of the crop sequence, EI management outyielded FP from 13 to 42%, depending on environmental conditions. Maize yield accounted formost of the variation (41–64%) of the accumulated grain yield of crop sequence, whether in EI as in FP. Averagegrain yield diffrences between EI and FP treatments were 274 g m−2 for maize, 69 g m−2 for wheat and -2 g m−2for soybean. Water and radiation productivities of the sequence were higher in EI than in FP (26% for water and17% for radiation; P < 0.0001), mainly because of increases in resource use effiencies. EI reduced partial factorproductivity of applied N, but improved partial nutrient balance for N as compared with FP. These reductions inpartial factor productivity of applied N were less than proportional than the increases in N rate. Moreover, in spiteof the higher N rate in EI respect to FP, N utilization effiency (NutE), i.e. grain per unit N uptake, was higher across all situations in EI. Our results showed that the challenge to obtain high grain yields by increasing N rate in amedium-input system could be achieved even with an increase in NutE. Grain yields improvements, and increasesin radiation and water productivity were reached by applying a set of agronomic practices that included improvedgenetics, crop and fertilizer N management englobed under EI concept

Prospecting the resilience of several Spanish ancient varieties of red grape under climate change scenarios

Background: Climate change results in warmer air temperatures and an uncertain amount and distribution of annual precipitations, which will directly impact rainfed crops, such as the grapevine. Traditionally, ancient autochthones grapevine varieties have been substituted by modern ones with higher productivity. However, this homogenization of genotypes reduces the genetic diversity of vineyards which could make their ability to adapt to challenges imposed by future climate conditions difficult. Therefore, this work aimed to assess the response of four ancient grapevine varieties to high temperatures under different water availabilities, focusing on plant water relations, grape technological and phenolic maturity, and the antioxidant capacity of the must. Methods: The study was conducted on fruit-bearing cuttings grown in pots in temperature-gradient greenhouses. A two-factorial design was established where two temperature regimes, ambient and elevated (ambient + 4 °C), were combined with two water regimes, full irrigation and post-veraison deficit irrigation, during fruit ripening. Results: There were significant differences among the ancient varieties regarding plant water relations and fruit quality. Conclusion: This research underlines the importance of evaluating the behavior of ancient grapevine varieties that could offer good options for the adaptation of viticulture to future climate condition

Carbon balance, partitioning and photosynthetic acclimation in fruit-bearing grapevine (Vitis vinifera L. cv. Tempranillo) grown under simulated climate change (elevated CO2, elevated temperature and moderate drought) scenarios in temperature gradient

Although plant performance under elevated CO2 has been extensively studied in the past little is known about photosynthetic performance changing simultaneously CO2, water availability and temperature conditions. Moreover, despite of its relevancy in crop responsiveness to elevated CO2 conditions, plant level C balance is a topic that, comparatively, has received little attention. In order to test responsiveness of grapevine photosynthetic apparatus to predicted climate change conditions, grapevine (Vitis vinifera L. cv. Tempranillo) fruit-bearing cuttings were exposed to different CO2 (elevated, 700 ppm vs. ambient, ca. 400 ppm), temperature (ambient vs. elevated, ambient +4 °C) and irrigation levels (partial vs. full irrigation). Carbon balance was followed monitoring net photosynthesis (AN, C gain), respiration (RD) and photorespiration (RL) (C losses). Modification of environment 13C isotopic composition (δ13C) under elevated CO2 (from −10.30 to −24.93‰) enabled the further characterization of C partitioning into roots, cuttings, shoots, petioles, leaves, rachides and berries. Irrespective of irrigation level and temperature, exposure to elevated CO2 induced photosynthetic acclimation of plants. C/N imbalance reflected the inability of plants grown at 700 ppm CO2 to develop strong C sinks. Partitioning of labeled C to storage organs (main stem and roots) did not avoid accumulation of labeled photoassimilates in leaves, affecting negatively Rubisco carboxylation activity. The study also revealed that, after 20 days of treatment, no oxidative damage to chlorophylls or carotenoids was observed, suggesting a protective role of CO2 either at current or elevated temperatures against the adverse effect of water stress

Novel, technical advance: a new grapevine transpiration prototype for grape berries and whole bunch based on relative humidity sensors

Grape berry transpiration is considered an important process during maturation, but scientific evidence is scarce. In the literature, there is only one report showing reduced maturation when bunch transpiration is artificially slowed down. Traditionally, grape berry transpiration has been measured by weighing grape berries on scale for a given time, correctly assuming that the weight reduction is due to water lost. Commercially available instruments adequate to measure gas exchange in small fruits are not suitable for whole grape berry bunch. Here, we present an open differential chamber system that can be used with isolated grape berries or alternatively with a whole grape berry bunch for measuring grape berry/bunch transpiration based on the use of relative humidity sensors from Vaisala. When used with isolated grape berries, open differential chamber system validation was made by using Tempranillo grape berries collected at different phenological stages. For the whole bunch transpiration prototype, two different validations were made. Firstly, measurements were made inserting inside the chamber an increasing number of Eppendorf tubes filled with water. Secondly, transpiration was measured in whole Tempranillo bunches sampled at different phenological stages. An important output of this work is that the fact of detaching the bunch from the plant did not change the bunch gas exchange rates at least for several hours

Sensitivity of grapevine phenology to water availability, temperature and CO2 concentration

In recent decades, mean global temperatures have increased in parallel with a sharp rise in atmospheric carbon dioxide (CO2) levels, with apparent implications for precipitation patterns. The aim of the present work is to assess the sensitivity of different phenological stages of grapevine to temperature and to study the influence of other factors related to climate change (water availability and CO2 concentration) on this relationship. Grapevine phenological records from 9 plantings between 42.75°N and 46.03°N consisting of dates for budburst, flowering and fruit maturity were used. In addition, we used phenological data collected from 2 years of experiments with grapevine fruit-bearing cuttings with two grapevine varieties under two levels of water availability, two temperature regimes and two levels of CO2. Dormancy breaking and flowering were strongly dependent on spring temperature, while neither variation in temperature during the chilling period nor precipitation significantly affected budburst date. The time needed to reach fruit maturity diminished with increasing temperature and decreasing precipitation. Experiments under semi-controlled conditions revealed great sensitivity of berry development to both temperature and CO2. Water availability had significant interactions with both temperature and CO2; however, in general, water deficit delayed maturity when combined with other factors. Sensitivities to temperature and CO2 varied widely, but higher sensitivities appeared in the coolest year, particularly for the late ripening variety, ‘White Tempranillo’. The knowledge gained in whole plant physiology and multi stress approaches is crucial to predict the effects of climate change and to design mitigation and adaptation strategies allowing viticulture to cope with climate change

7th Drug hypersensitivity meeting: part two

No abstract availabl