Targeted CRISPR/Cas9-Based Knock-Out of the Rice Orthologs TILLER ANGLE CONTROL 1 (TAC1) in Poplar Induces Erect Leaf Habit and Shoot Growth

Pyramidal-, erect- or upright-growing plant forms are characterized by narrow branch angles of shoots and leaves. The putative advantage of upright-leaf and shoot habit could be a more efficient penetration of light into lower canopy layers. Pyramidal genotypes have already been reported for various tree genotypes including peach. The paralogous rice ortholog TILLER ANGLE CONTROL 1 (TAC1) has been proposed to be the responsible gene for upright growth. However, it has not really been demonstrated for any of the pyramidal tree genotypes that a knock-out mutation of the TAC1 gene is causing pyramidal plant growth. By in silico analyses, we have identified a putative rice TAC1 ortholog (Potri.014G102600, “TAC-14”) and its paralog (Potri.002G175300, “TAC-2”) in the genome of P. trichocarpa. Two putative PcTAC1 orthologs in the P. × canescens clone INRA 717-1B4 were successfully knocked-out by applying a transgenic CRISPR/Cas9-approach. The mutants were molecularly analyzed and phenotyped over a period of three years in a glasshouse. Our results indicate that the homozygous knock-out of “TAC-14” is sufficient to induce pyramidal plant growth in P. × canescens. If up to twice as many pyramidal individuals were planted on short rotation coppices (SRCs), this could lead to higher wood yield, without any breeding, simply by increasing the number of trees on a default field size.

Can improved canopy light transmission ameliorate loss of photosynthetic efficiency in the shade? An investigation of natural variation in Sorghum bicolor.

Previous studies have found that maximum quantum yield of CO2 assimilation (ΦCO2,max,app) declines in lower canopies of maize and Miscanthus, a maladaptive response to self-shading. These observations were limited to single genotypes, leaving it unclear that the maladaptive shade response is a general property of this C4 grass tribe, the Andropogoneae. We explored the generality of this maladaptation by testing the hypothesis that erect leaf forms (erectophiles), which allow more light into the lower canopy, suffer less of a decline in photosynthetic efficiency than drooping leaf (planophile) forms. On average, ΦCO2,max,app declined 27% in lower canopy leaves across 35 accessions, but the decline was over twice as great in planophiles than in erectophiles. The loss of photosynthetic efficiency involved a decoupling between electron transport and assimilation. This was not associated with increased bundle sheath leakage, based on 13C measurements. In both planophiles and erectophiles, shaded leaves had greater leaf absorptivity and lower activities of key C4 enzymes than sun leaves. The erectophile form is considered more productive because it allows a more effective distribution of light through the canopy to support photosynthesis. We show that in sorghum, it provides a second benefit, maintenance of higher ΦCO2,max,app to support efficient use of that light resource.

Distribution record of Musa borneensis var. sarawakensis Becc. and Musa campestris var. sarawakensis Becc. in West Kalimantan, Indonesia

Borneo Island has a large number of wild banana species. As a part of Borneo Island, West Kalimantan has limited information about the diversity of wild bananas. This research aims to update the record distribution of wild bananas from Bonti District of Sanggau Regency and to determine their morphological characteristics. Exploration method and resident information were used in this study. Two species of wild bananas have been identified and considered as new distribution records in West Kalimantan Province, namely-Musa borneensis var. sarawakensis with morphological character pseudostem red-purple colour, sparse black-purple blotches at petiole base, leaf base shape rounded on both sides, male bud red-purple colour and Musa campestris var. sarawakensis with morphological character pseudostem yellow-green colour, inflorescence erect, leaf base one side rounded and one-pointed, the dorsally pink-purple and ventrally pink-purple colour of bract.

Effects of Tagetes erecta gel on experimentally induced oral ulcer model in rats

Tagetes erecta(African marigold) has various medicinal values. The present study has been undertaken to evaluate the effects of extracts of the fresh leaves and flowers of Tagetes erecta on oral ulcer models in Wistar albino rats. The anti-ulcer activity of the extracts of tagetes erecta (2.5% and 5%) was compared between the leaf and flower and also with the standard drug, Triamcinolone. Phytochemical screening of plant extract, extract action on oral ulcer and histopathology analysis were carried out. Tagetes erecta leaf and flower extracts have showed the presence of alkaloids, flavonoids, and carotenoids. Results showed that Tagetes erect leaf extract showed significant oral ulcer protective activity (83.6%) when compared with the standard drug Triamcinolone. In the present work, it can be concluded that the hydro alcoholic leaf and flower extractHistopathologys of Tagetes erectagel have better potential against oral ulcer which supports the traditional claims in folklore medicine.

Sabal lougheediana (Arecaceae), a critically endangered, endemic palm species from Bonaire

A new palm species, Sabal lougheediana, is described and illustrated. This critically endangered island endemic, native solely to Bonaire, is characterized by a compact crown of leaves, erect leaf segments, distinctive leaf scars, and frequently vascularized fiber bundles in leaflet transection. Detail on history, morphology, range, habitat, and conservation status is presented, along with a diagnostic key.

Exploring agronomic strategies to improve oat productivity and control weeds: leaf type, row spacing, and planting density

The trade-off between crop production and weed control is a fundamental scientific issue, as it is frequently influenced by individual crop competitive ability, population density, and planting pattern. A 2 yr field study was conducted to examine the relationship between planting density and row spacing, using two contrasting oat varieties. On average, high planting density (480 plants m−2) reduced weed biomass at oat maturity by 59% in 2012 and by 56% in 2013, when compared with a low density (120 plants m−2). The droopy-leaf variety suppressed weed biomass by up to 69% and weed density up to 72%, compared with the erect-leaf variety. In a drier year, the greatest grain yield was achieved with the droopy-leaf variety under the intermediate density, while in 2013, the erect-leaf variety under the high density had similar yield to the droopy-leaf variety at the intermediate density. A general trend was that increasing plant density suppressed weed infestation, and promoted crop biomass and yield. The droopy-leaf variety exhibited a strong competitive ability under the intermediate planting density, while the erect-leaf variety had a strong competitive ability under the high density. Taken together, there was a complex variety-by-environment interaction to achieve the balance between crop production and weed suppression, which was mediated by growing-season conditions.