Biology subjects

Rodriguez-Concepcion, M.

Publications and source records attributed to Rodriguez-Concepcion, M..

4 recordsLinked to original sources

bioRxiv2021

Manipulation of carotenoid metabolism stimulates biomass and stress tolerance in tomato

Improving yield, nutritional value and tolerance to abiotic stress are major targets of current breeding and biotechnological approaches that aim at increasing crop production and ensuring food security. Metabolic engineering of carotenoids, the precursor of Vitamin-A and plant hormones that regulate plant growth and response to adverse growth conditions, has been mainly focusing on provitamin A biofortification or the production of high-value carotenoids. Here, we show that the introduction of a single gene of the carotenoid biosynthetic pathway in different tomato cultivars simultaneously improved photosynthetic capacity and tolerance to various abiotic stresses (e.g., high light, salt, and drought), caused an up to 77% fruit yield increase and enhanced fruits provitamin A content and shelf life. Our findings pave the way for developing a new generation of crops that combine high productivity and increased nutritional value with the capability to cope with climate change-related environmental challenges.

plant biology↗

bioRxiv2021

Carotenoid and tocopherol fortification of zucchini fruits using a viral RNA vector

Carotenoids and tocopherols are health-promoting metabolites in livestock and human diets. Some important crops have been genetically modified to increase their content. Although the usefulness of transgenic plants to alleviate nutritional deficiencies is obvious, their social acceptance has been controversial. Here, we demonstrate an alternative biotechnological strategy for carotenoid and tocopherol fortification of edible fruits in which no transgenic DNA is involved. A viral RNA vector derived from Zucchini yellow mosaic virus (ZYMV) was modified to express a bacterial phytoene synthase (crtB), and inoculated in zucchini (Cucurbita pepo L.) leaves nurturing pollinated flowers. After the viral vector moved to the developing fruit and expressed crtB, the rind and flesh of the fruits developed yellow-orange rather than green color. Metabolite analyses showed a substantial enrichment in health-promoting carotenoids, such as - and {beta}-carotene (pro-vitamin A), lutein and phytoene, in both rind and flesh. Considerably higher accumulation of - and {gamma}-tocopherol was also detected, particularly in fruit rind. Although this strategy is perhaps not free from controversy due to the use of genetically modified viral RNA, our work does demonstrate the possibility of metabolically fortifying edible fruits using an approach in which no transgenes are involved.

plant biology↗

bioRxiv2021

The intrinsic chaperone network of Arabidopsis stem cells confers protection against proteotoxic stress

The biological purpose of plant stem cells is to maintain themselves while providing new pools of differentiated cells that form organs and rejuvenate or replace damaged tissues1-3. Protein homeostasis, or proteostasis, is required for cell function and viability4-7. However, the link between proteostasis and plant stem cell identity remains unknown. In contrast to their differentiated counterparts, we find that root stem cells can prevent the accumulation of aggregated proteins even under proteotoxic stress conditions such as heat stress or proteasome inhibition. Notably, root stem cells exhibit enhanced expression of distinct chaperones that maintain proteome integrity. Particularly, intrinsic high levels of the TRiC/CCT chaperonin determine stem cell maintenance and their remarkable ability to suppress protein aggregation. Overexpression of CCT8, a key activator of TRiC/CCT assembly8, is sufficient to ameliorate protein aggregation in differentiated cells and confer resistance to proteotoxic stress in plants. Taken together, our results indicate that enhanced proteostasis mechanisms in stem cells could be an important requirement for plants to persist under extreme environmental conditions and reach extreme long ages. Thus, proteostasis of stem cells could provide insights to design and breed plants tolerant to environmental challenges caused by the climate change.

plant biology↗

bioRxiv2020

Light quality signals generated by vegetation shade facilitate acclimation to reduced light quantity in shade-avoider plants

O_LIWhen growing in search for light, plants can experience continuous or occasional shading by other plants. Plant proximity causes a decrease in the ratio of red to far red light (low R:FR) due to the preferential absorbance of red light and reflection of far red light by photosynthetic tissues of neighboring plants. This signal is often perceived before actual shading causes a reduction in photosynthetically active radiation (low PAR). C_LIO_LIHere we investigated elongation, photosynthesis and photoacclimation responses in several Brassicaceae species to explore the possible connections between low R:FR and low PAR. C_LIO_LIA negative correlation was found in shade-tolerant Cardamine hirsuta and shade-avoider Arabidopsis thaliana seedlings (e.g., shade-tolerance was associated with a good adaptation to low PAR but a poor or null response to low R:FR exposure). However, they could be genetically uncoupled. Most interestingly, exposure to low R:FR of shade-avoider plants improved their photoacclimation to low PAR by triggering changes in photosynthesis-related gene expression, pigment accumulation and chloroplast ultrastructure. C_LIO_LIThese results indicate that low R:FR signaling unleashes molecular, metabolic and developmental responses that allow shade-avoider plants (including most crops) to adjust their photosynthetic capacity in anticipation of eventual shading by nearby plants. C_LI

plant biology↗