Close-range hyperspectral image analysis for the early detection of stress responses in individual plants in a high-throughput phenotyping platform

The potential of close-range hyperspectral imaging (HSI) as a tool for detecting early drought stress responses in plants grown in a high-throughput plant phenotyping platform (HTPPP) was explored. Reflectance spectra from leaves in close-range imaging are highly influenced by plant geometry and its specific alignment towards the imaging system. This induces high uninformative variability in the recorded signals, whereas the spectral signature informing on plant biological traits remains undisclosed. A linear reflectance model that describes the effect of the distance and orientation of each pixel of a plant with respect to the imaging system was applied. By solving this model for the linear coefficients, the spectra were corrected for the uninformative illumination effects. This approach, however, was constrained by the requirement of a reference spectrum, which was difficult to obtain. As an alternative, the standard normal variate (SNV) normalisation method was applied to reduce this uninformative variability. Once the envisioned illumination effects were eliminated, the remaining differences in plant spectra were assumed to be related to changes in plant traits. To distinguish the stress-related phenomena from regular growth dynamics, a spectral analysis procedure was developed based on clustering, a supervised band selection, and a direct calculation of a spectral similarity measure against a reference. To test the significance of the discrimination between healthy and stressed plants, a statistical test was conducted using a one-way analysis of variance (ANOVA) technique. The proposed analysis techniques was validated with HSI data of maize plants (Zea mays L.) acquired in a HTPPP for early detection of drought stress in maize plant. Results showed that the pre-processing of reflectance spectra with the SNV effectively reduces the variability due to the expected illumination effects. The proposed spectral analysis method on the normalized spectra successfully detected drought stress from the third day of drought induction, confirming the potential of HSI for drought stress detection studies and further supporting its adoption in HTPPP

Viabilidad Financiera del Nuevo Banco de Desarrollo de los BRICS como alternativa para préstamo y empréstitos para los Estados Centroamericano, 2016-2021.

Situación actual de los Estados Centroamericanos para acceder a préstamos y empréstitos -- El nuevo Banco de Desarrollo de los BRICS—Viabilidad Financiera del Nuevo Banco de Desarrollo de los BRICS para otorgar préstamos y empréstitos a los Estados Centroamericanos – Situación actual de los Estados Centroamericanos para acceder a préstamos y empréstitos

PENGALAMAN BERSAHABAT DAN DINAMIKA INTERAKSI ANAK SELECTIVE MUTISM DI SEKOLAH INKLUS

Pengalaman bersahabat dan menjalin relasi interpersonal dengan teman sebaya merupakan sebuah fase penting bagi perkembangan diri seorang remaja, tanpa terkecuali remaja dengan SM (Selective Mutism). Persahabatan dipercaya akan membentuk kepribadian seseorang dan berkontribusi penting dalam kehidupan seseorang. Tujuan penelitian ini adalah untuk mengetahui deskripsi dan gambaran pengalaman berteman anak SM, pola relasi yang ditampilkan oleh anak SM ketika menjalin hubungan pertemanan dengan teman sebayanya di sekolah, dan penerimaan lingkungan sekolah terhadap anak SM. Berdasarkan studi kasus yang dilakukan oleh peneliti, hasil yang didapatkan menunjukkan bahwa subjek penelitian mengalami kesulitan dalam mendeskripsikan pengalamannya berteman karena memang ia tidak pernah berteman dekat dengan siapapun sebelumnya, kemudian pola relasi yang ditampilkan juga menunjukkan bahwa subjek cenderung pasif dan diam. Kesimpulan dari studi kasus ini adalah subjek memang memiliki kesulitan dalam berteman dan berkomunikasi dengan lingkungannya meskipun lingkungannya sebenarnya menerimanya. Kata kunci: persahabatan, remaja, selective mutis

Role of Arabidopsis UV RESISTANCE LOCUS 8 in plant growth reduction under osmotic stress and low levels of UV-B

In high-light environments, plants are exposed to different types of stresses, such as an excess of UV-B, but also drought stress which triggers a common morphogenic adaptive response resulting in a general reduction of plant growth. Here, we report that the Arabidopsis thaliana UV RESISTANCE LOCUS 8 (UVR8) gene, a known regulator of the UV-B morphogenic response, was able to complement a Saccharomyces cerevisiae osmo-sensitive mutant and its expression was induced after osmotic or salt stress in Arabidopsis plants. Under low levels of UV-B, plants overexpressing UVR8 are dwarfed with a reduced root development and accumulate more flavonoids compared to control plants. The growth defects are mainly due to the inhibition of cell expansion. The growth inhibition triggered by UVR8 overexpression in plants under low levels of UV-B was exacerbated by mannitol-induced osmotic stress, but it was not significantly affected by ionic stress. In contrast, uvr8-6 mutant plants do not differ from wild-type plants under standard conditions, but they show an increased shoot growth under high-salt stress. Our data suggest that UVR8-mediated accumulation of flavonoid and possibly changes in auxin homeostasis are the underlying mechanism of the observed growth phenotypes and that UVR8 might have an important role for integrating plant growth and stress signals.This work was supported by the Interuniversity Attraction Poles Programme (IUAP P7/29 'MARS') initiated by the Belgian Science Policy Office, by grants from Ghent University (Bijzonder Onderzoeksfonds Methusalem project no. BOF08/01M00408), and by grants to the MIUR project FIRB Plant-STRESS.Fasano, R.; Gonzalez, N.; Tosco, A.; Dal Piaz, F.; Docimo, T.; Serrano Salom, R.; Grillo, S.... (2014). Role of Arabidopsis UV RESISTANCE LOCUS 8 in plant growth reduction under osmotic stress and low levels of UV-B. Molecular Plant. 7(5):773-791. https://doi.org/10.1093/mp/ssu002S7737917

Molecular systems governing leaf growth: from genes to networks: Molecular systems governing leaf growth: from genes to networks

Molecular systems governing leaf growth: from genes to networks. Molecular systems governing leaf growth: from genes to network

Plant cell factories in the post-genomic era:New ways to produce designer secondary metabolites

Plants synthesize an extensive array of secondary metabolites, often with highly complex structures. Currently, most pharmaceutically important secondary metabolites are isolated from wild or cultivated plants because their chemical synthesis is not economically feasible. Biotechnological production in plant cell cultures is an attractive alternative, but to date this has had only limited commercial success because of a lack of understanding of how these metabolites are synthesized. Here, we discuss how the spectacular advances in plant genomics and metabolite profiling offer unprecedented possibilities to explore the extraordinary complexity of the plant biochemical capacity. State-of-the art genomics tools can be used to enhance the production of known target metabolites or to synthesize entire novel compounds by so-called combinatorial biochemistry in cultivated plant cells