A dual-omics approach for profiling plant responses to biostimulant applications under controlled and field conditions

A comprehensive approach using phenomics and global transcriptomics for dissecting plant response to biostimulants is illustrated with tomato (Solanum lycopersicum cv. Micro-Tom and Rio Grande) plants cultivated in the laboratory, greenhouse, and open field conditions. Biostimulant treatment based on an Ascophyllum nodosum extract (ANE) was applied as a foliar spray with two doses (1 or 2 l ha-1) at three different phenological stages (BBCH51, BBCH61, and BBCH65) during the flowering phase. Both ANE doses resulted in greater net photosynthesis rate, stomatal conductance, and fruit yield across all culture conditions. A global transcriptomic analysis of leaves from plants grown in the climate chamber, revealed a greater number of differentially expressed genes (DEGs) with the low ANE dose compared to the greater one. The second and third applications induced broader transcriptome changes compared to the first one, indicating a cumulative treatment effect. The functional enrichment analysis of DEGs highlighted pathways related to stimulus-response and photosynthesis, consistent with the morpho-physiological observations. This study is the first comprehensive dual-omics approach for profiling plant responses to biostimulants across three different culture conditions

Transcriptomic and physiological approaches to decipher cold stress mitigation exerted by brown-seaweed extract application in tomato

Chilling temperatures represent a challenge for crop species originating from warm geographical areas. In this situation, biostimulants serve as an eco-friendly resource to mitigate cold stress in crops. Tomato (Solanum lycopersicum L.) is an economically important vegetable crop, but quite sensitive to cold stress, which it encounters in both open field and greenhouse settings. In this study, the biostimulant effect of a brown-seaweed extract (BSE) has been evaluated in tomato exposed to low temperature. To assess the product effects, physiological and molecular characterizations were conducted. Under cold stress conditions, stomatal conductance, net photosynthesis, and yield were significantly (p ≤ 0.05) higher in BSE-treated plants compared to the untreated ones. A global transcriptomic survey after BSE application revealed the impact of the BSE treatment on genes leading to key responses to cold stress. This was highlighted by the significantly enriched GO categories relative to proline (GO:0006560), flavonoids (GO:0009812, GO:0009813), and chlorophyll (GO:0015994). Molecular data were integrated by biochemical analysis showing that the BSE treatment causes greater proline, polyphenols, flavonoids, tannins, and carotenoids contents.The study highlighted the role of antioxidant molecules to enhance tomato tolerance to low temperature mediated by BSE-based biostimulant

Energy crop rotation possibilities

Introduction. The increased dependence of energy and/or agriculture crop systems on external inputs (fertilizer, pesticides) constitutes a challenge to their long-term productivity because of environmental and logistics constrains. Alternatively, crop rotation systems offer the possibility to reduce the dependence on external inputs through internal nutrient recycling, maintenance of the long-term productivity of the land, control of diseases and pests, and increased crop yields. Among the large variety of annual, herbaceous perennial, and woody crops that could be included in energy production systems, annual crops are, in fact, the ones that are intensively managed in rotations. Material and methods. The most prominent annual energy crops selected for this review, based on their economic significance, geographical distribution and suitability to the climatic conditions, are: sweet and fiber sorghum, flax, rapeseed, sunflower, hemp and Ethiopian mustard. The analysis and literature review on the rotation possibilities for each of these species was based on their biological and environmental interactions. Results and discussion. The available information suggests that introducing energy crops alongside traditional agriculture crop rotation systems is possible, especially for well-known crops such as rapeseed, sorghum and sunflower. On the other hand, as the management of new energy crops such as flax, hemp and Ethiopian mustard is not well developed, research on rotations possibilities and crop sequences including these species should be given high priority. Possible rotation systems dedicated exclusively to produce feedstock for bioenergy purposes are also discussed. Conclusions. A rotation system that could optimize the utilization of soil resources and fit the environmental conditions of Mediterranean climates is wheat (legume) \u2013 maize \u2013 sunflower \u2013 sorghum \u2013 fallow. In temperate climates a rapeseed \u2013 cereal (e.g. wheat, barley, oat) \u2013 cereal \u2013 rapeseed rotation could be the best choice

Switchgrass for bioenergy production

The main characteristics of switchgrass were presented along with its benefits in term of environment and carbon sequestration

The effects of the degree of soil cover with an impervious sheet on the establishment of tree seedlings in an arid environment

Abstract Low precipitation and high evaporation rates hinder the establishment of tree seedlings in arid environments. The objective of this study was to assess the effect of covering different fractions (0, 30, 70 and 100%) of the wetted area surrounding seedlings of Acacia saligna (Labill.) H.L. Wendl. with a black polyethylene sheet on the seedlings development and water use. The cover treatments were applied to plots with and without Acacia seedlings. Within the mulched areas at all depths, soil temperatures close to the edges were lower than at the corresponding depth close to the center, but still higher than in the non-mulched plots. In plots with Acacia seedlings, the total soil water losses were similar among treatments. However, the cumulative evaporative losses near the soil surface were lower with larger mulched areas. During early growth stages, roots grew deeper in the 30% mulch treatment and more laterally in the other mulched treatments. The nonmulched treatment produced the smallest root system. Larger canopies developed in the mulched treatments and the gross water use efficiency increased with the increasing fraction of the mulched area. Optimum utilization of stored soil water and seedling development were attained with the 70% mulch treatment

Water uptake efficiency and above- and belowground biomass development of sweet sorghum and maize under different water regimes

Lately sweet sorghum (S) has attracted great interest as an alternative feedstock for biofuel production due to its high yielding potential and better adaptation to drought than maize (M). However, little is known about the response of newly developed sweet sorghum genotypes to water deficits, especially at the root level and its water uptake patterns. The objective of this study was to compare the water uptake capacity, growth and developmental characteristics at the root and canopy levels of a sweet sorghum hybrid (Sorghum bicolor cv. Sucro 506) with those of maize (Zea mays cv. PR32F73) at two water regimes. The trial was setup in a total of 20 rhizotrons (1 m3), where calibrated soil moisture probes were installed for monitoring and adjusting the soil moisture content to 25% (well-watered, W) and 12% (drought stress, D). Results DS was able to sustain its physiological activity close to that of WS plants, while maize was not. The biomass production potential of DS was reduced about 38%, while in maize the reduction was 47%. The water use efficiency (WUE), however, was increased by 20% in sweet sorghum and reduced in 5% in maize. Moreover, in contrast to maize the root length density and water uptake capacity of DS was enhanced. Root water uptake efficiency in DM was sustained close to its potential, but not in sweet sorghum. In summary, the better adaptation to drought of sweet sorghum is explained by increased WUE, sustained physiological activity and enlarged root system. It is also associated with a reduced water uptake efficiency compared to its control but maintained compared to maize

Energy crops in rotation: a review

The area under energy crops has increased tenfold over the last 10 years, and there is large consensus that the demand for energy crops will further increase rapidly to cover several millions of hectares in the near future. Information about rotational systems and effects of energy crops should be therefore given top priority. Literature is poor and fragmentary on this topic, especially about rotations in which all crops are exclusively dedicated to energy end uses. Well-planned crop rotations, as compared to continuous monoculture systems, can be expected to reduce the dependence on external inputs through promoting nutrient cycling efficiency, effective use of natural resources, especially water, maintenance of the long-term productivity of the land, control of diseases and pests, and consequently increasing crop yields and sustainability of production systems. The result of all these advantages is widely known as crop sequencing effect, which is due to the additional and positive consequences on soil physicalechemical and biological properties arising from specific crops grown in the same field year after year. In this context, the present review discusses the potential of several rotations with energy crops and their possibilities of being included alongside traditional agriculture systems across different agro-climatic zones within the European Union

Are we ready to cultivate sweet sorghum as a bioenergy feedstock? A review on field management practices

This review discusses the potential production for energy purposes of sweet sorghum (Sorghum bicolor L.), a C4 crop native to tropical areas with juicy stalks rich in sugars from which ethanol could be produced at lower costs than from starchy crops like maize. The growing interest in bioenergy and particularly in bioethanol is a great challenge for this relatively new crop that could be used for both thermo-electrical energy and biofuel. Nonetheless, the quantitative and qualitative production of sweet sorghum strongly depends on the use of appropriate and improved agronomic management techniques which is, in some aspects, still largely unknown. This review attempts to gather the sparse information on best agricultural practices for sweet sorghum, still very much a wild species in many aspects, while identifying the weak points that need to be deepened in further researches, especially under temperate climates. Sweet sorghum is a row crop and therefore the agronomic management and other well known cultural methods used for conventional row crops such as maize can be adapted. In general, low input requirements, low production costs, drought resistance, versatility, and high yields gives to sweet sorghum a better energy balance compared to other competing energy crops, especially if bagasse is also processed to energy. In non-traditional potential growing areas (such as in temperate climates of Europe) where productivity/adaptation improvements through genetically modified crops is not allowed, appropriate and sustainable agricultural practices constitute the most immediate option to improve yields. Based on scientific reports, research efforts seem particularly needed for harvesting techniques, and handling and storing