Transformation of Plantation Forestry Productivity for Climate Change Mitigation and Adaptation.

The protection of natural forests as the major land-based biotic sink of carbon is regarded as a priority for climate action, and zero deforestation is an accepted global imperative. Sustainable intensification of plantation forestry will be essential to meet escalating, shifting, and diversifying demand for forest products if logging pressure on natural forests is to be decreased. Substitution strategies involves enhanced offtake from plantation forestry into long life-cycle products, opening up new options for medium- to long-term carbon drawdown, downstream decarbonization, and fossil fuel displacement in the construction and chemicals sectors. However, under current plantation productivity levels, it has been projected that by 2050, supply could provide as little as 35% of demand. This could be further exacerbated by climate change. To mitigate this shortfall, to avoid ensuing catastrophic logging pressure on natural forests, and to ensure that downstream decarbonization and fossil fuel substitution strategies are feasible, a dramatic step change in plantation productivity is required. This is particularly necessary in developing countries where increases in per capita demand and pressure on natural forests will be the most acute.

Five-years post commercial approval monitoring of eucalyptus H421.

Eucalyptus comprises the largest planted area of cultivated production forest in Brazil. Genetic modification of eucalyptus can provide additional characteristics for increasing productivity, protecting plant yield, and potentially altering fiber for various industrial uses. With this objective, a transgenic eucalyptus variety, event H421, received regulatory approval for commercial release after 6 years of approved risk assessment studies by the Brazilian National Technical Biosafety Commission (CTNBio) in 2015, becoming the first approved genetically modified (GM) eucalyptus in the world. GM event H421 enables increased plant biomass accumulation through overexpression of the Arabidopsis 1,4-ß-endoglucanase Cel1, which remodels the xyloglucan-cellulose matrix of the cell wall during development to promote cell expansion and growth. As required, in that time, by the current normative from CTNBio, a post-commercial release monitoring plan for H421 was submitted, incorporating general surveillance for five consecutive years with the submission of annual reports. The monitoring plan was conducted on fields of H421 progenies, with conventional clones as comparators, cultivated in representative regions where eucalyptus is cultivated in the states of São Paulo, Bahia, and Maranhão, representing Southeast, Northeast, and Northern Brazil. Over the course of the five-year general surveillance monitoring plan for the approved GM eucalyptus H421, no adverse effect that could impact the biosafety of the commercially approved event was identified. Additionally, the GM eucalyptus exhibited behavior highly consistent with that of conventional commercial clones. Therefore, there was no need for an extra risk assessment study of a case-specific monitoring plan. The results show the importance of continuously updating the regulation norms of governmental agencies to align with scientific advances.

The Modification of Cell Wall Properties by Expression of Recombinant Resilin in Transgenic Plants.

Plant tissue is composed of many different types of cells. Plant cells required to withstand mechanical pressure, such as vessel elements and fibers, have a secondary cell wall consisting of polysaccharides and lignin, which strengthen the cell wall structure and stabilize the cell shape. Previous attempts to alter the properties of the cell wall have mainly focused on reducing the amount of lignin or altering its structure in order to ease its extraction from raw woody materials for the pulp and paper and biorefinery industries. In this work, we propose the in vivo modification of the cell wall structure and mechanical properties by the introduction of resilin, an elastic protein that is able to crosslink with lignin monomers during cell wall synthesis. The effects of resilin were studied in transgenic eucalyptus plants. The protein was detected within the cell wall and its expression led to an increase in the elastic modulus of transgenic stems. In addition, transgenic stems displayed a higher yield point and toughness, indicating that they were able to absorb more energy before breaking.