Editorial: Current and future perspectives for controlled environment agriculture (CEA) in the 21st century

Controlled Environment Agriculture (CEA) is the production of crops under protected environments by optimizing climate and inputs (water, feed, chemicals, energy, labor, etc.). The aim is to maximize crop quality and quantity, extend the growing season and reduce inputs. However, with increasing costs of energy, labour, and consumables, major concerns in the 21st century exist around the sustainability of CEA. Fortunately, decades of innovation made by pioneers in areas such as breeding, greenhouse infrastructure, energy, computer science and more, have created the potential capacity to address these issues directly. In this Research Topic, we delve into the fascinating and dynamic world of CEA research and explore the latest research and innovative approaches that offer promise for improving sustainability features of CEA. Towards that aim, this Research Topic invited manuscripts focusing on multi-disciplinary approaches and novel technologies of CEA, summing up to five original research articles. The papers represent an eclectic mix that demonstrates the range of research aspects on CEA such as optimising environment (light quality, quantity, etc.), optimising crop growth strategies (indoor pest control) and the application of AI and computing technologies along with sensor development.</p

Additional file 1: of Nitrogen remobilisation facilitates adventitious root formation on reversible dark-induced carbohydrate depletion in Petunia hybrida

Experiments 1-9 of nitrogen preconditioning of cuttings. (PDF 22 kb

Additional file 1: of Changes in nitrogen availability lead to a reprogramming of pyruvate metabolism

Table S1. Primers sequence that were used for qPCR analysis (PDF 404 kb

Additional file 2: of Changes in nitrogen availability lead to a reprogramming of pyruvate metabolism

Table S2. List of the all genes regulated by N status. You can find the table in the attached excel file. The relative expression was determined by microarray. The values are presented log2 (fold changes (FC)). Values of Low N are relative to corresponding time point of control. Whereas Values of N resupply are relative to Low N (20 DAG). (XLSX 634 kb

Cluster analysis.

<p>Two major clusters of genes specifically induced during different phases of AR formation created via K-means clustering method by Genesis software. Three types of associated expression graphs of each cluster are shown. SEP: Sink Establishment Phase; RP: Recovery Phase; MP: Maintenance Phase.</p

Presentation_1_The Defense-Related Isoleucic Acid Differentially Accumulates in Arabidopsis Among Branched-Chain Amino Acid-Related 2-Hydroxy Carboxylic Acids.PDF

<p>The branched-chain amino acid (BCAA) related 2-hydroxy carboxylic acid isoleucic acid (ILA) enhances salicylic acid-mediated pathogen defense in Arabidopsis thaliana. ILA has been identified in A. thaliana as its glucose conjugate correlated with the activity of the small-molecule glucosyltransferase UGT76B1, which can glucosylate both salicylic acid and ILA in vitro. However, endogenous levels of the ILA aglycon have not yet been determined in planta. To quantify ILA as well as the related leucic acid (LA) and valic acid (VA) in plant extracts, a sensitive method based on the derivatization of small carboxylic acids by silylation and gas chromatography–mass spectrometric analysis was developed. ILA was present in all species tested including several monocotyledonous and dicotyledonous plants as well as broadleaf and coniferous trees, whereas LA and VA were only detectable in a few species. In A. thaliana both ILA and LA were found. However, their levels varied during plant growth and in root vs. leaves. ILA levels were higher in 2-week-old leaves and decreased in older plants, whereas LA exhibited a reverted accumulation pattern. Roots displayed higher ILA and LA levels compared to leaves. ILA was inversely related to UGT76B1 expression level indicating that UGT76B1 glucosylates ILA in planta. In contrast, LA was not affected by the expression of UGT76B1. To address the relation of both 2-hydroxy acids to plant defense, we studied ILA and LA levels upon infection by Pseudomonas syringae. LA abundance remained unaffected, whereas ILA was reduced. This change suggests an ILA-related attenuation of the salicylic acid response. Collectively, the BCAA-related ILA and LA differentially accumulated in Arabidopsis, supporting a specific role and regulation of the defense-modulating small-molecule ILA among these 2-hydroxy acids. The new sensitive method will pave the way to further unravel their role in plants.</p

cDNA library of petunia cuttings.

<p>Classification of putative proteins into different categories of metabolism during various developmental stages of adventitious root formation in petunia cuttings. Numbers of putative proteins in different categories of the KEGG superpathway are shown in parentheses. Total protein number was 607 (out of 4,700 EST‘s).</p

Schematic illustration of metabolic pathways regulated during AR formation in petunia cuttings.

<p>In the figure, only important induced key genes in primary metabolism, cell replication machinery, signalling and membrane transport are included. Induced genes are shown in red color. Because the observed gene expression patterns in R and M phases were not significantly different and to simplify the figure, only two phases have been illustrated. (<b>A</b>) SE phase (<b>B</b>) R and M phases. NT: nitrate transporter, PT: phosphate transporter, Zn/Fe.T: zinc/iron transporter, Cyt. Inv: cytosolic invertase; CW Inv: cell wall invertase; SuT: sucrose transporter; PFK: phosphofructokinase, HXK: hexokinase, RNR: ribonucleotide reductase; PEPC: phosphoenolpyruvate carboxylase; H.A.CoA DH: 3-hydroxyacyl-CoA dehydrogenase; E.CoA hydratase: enoyl-CoA hydratase; Pro: proline; ProDH: proline dehydrogenase; P5CDH: pyrroline-5-carboxylate dehydrogenase; Met: methionine; SAMS: S-adenosylmethionine synthase; SAM: S-adenosylmethionine.</p

Negative correlation between the significance of time and replicate effects.

<p>Plot of -Log10 of the significance of the replicate effect (Y-axis) versus the -Log10 of the significance of the time effect (X-axis), indicating a much stronger time effect than undesired variation between replicates. Minimum P-value within replicates of all time points is located on the abscissa (X-axis) and minimum P-value of all ratios compared to 0hpe is located on the ordinate (Y-axis).</p

Comparison of fold change differences of seven genes specifically induced during different phases of AR formation based on microarray and Real-Time qPCR.

<p>Each value in qPCR data is represented by the mean of three independent replicates ± standard error. Sequence ID for each gene is: pectinase (GO_drpoolB-CL9530Contig1), glucose transporter (cn1111), nitrate transporter (cn8317), F-box family protein (IP_PHBS008L07u), ubiquitin-protein ligase (IP_PHBS007P04u), trehalose-p-phosphatase (cn3641) and zinc/iron transporter (cn5371).</p