Successes and failures developing biotechnological tools in a model plant to improve crops. The long way from the growth chamber to the greenhouse and from the greenhouse to the field.

RIBICHICH, KARINA F.; CABELLO, JULIETA V.; CAMPI, MABEL; OTEGUI, MARÍA E.; RAINERI, JÉSICA; FRANCO, MANUEL; CHAN, RAQUEL L.

Paraná

Congreso; 54th Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2018

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Worldwide research on Plant Molecular Biology has been carried out mostly working with model species. Among them, Arabidopsis thaliana isthe most studied one due to several characteristics: first sequenced plant genome, short life cycle, small size, availability of genetic tools, etc.However, when the aim is to improve crops, using the knowledge acquired in such model, there is a long way full of obstacles and stop points tobe traversed. An additional and independent complicated route appears towards the front when traits tested in crops in a culture chamber need tobe evaluated in a greenhouse and field trials. HaHB4 is a sunflower transcription factor, shown as able to confer drought and salinity tolerance inArabidopsis. It was introduced as transgene in soybean and in wheat. Culture chamber, greenhouse and field trials in different environmentswere conducted indicating that beneficial traits were conserved between the model and the crops. This technology has almost ended the long wayand soybean HaHB4 became a rare successful case because it is expected to be released to the market in 2018/2019. Data from last summer inArgentina, where a severe drought occurred, indicated variations in biomass and seed yield for transgenic HaHB4, control and commercialgenotypes in three environments. Under heat stress or drought, seed yield of HaHB4 plants was always the largest (26%-95% yield increase),outyielded by the commercial line only in one well-watered environment. On the other hand and in spite of robust experimental results, wheatHaHB4 could not achieve the final goal; its release was stopped in the Agroindustry Ministry. In our Institute, other sunflower transcriptionfactors were introduced in crops aiming at testing their capability to promote benefits. In a few cases, the transgenes were not expressed asexpected, probably due to inadequate genetic constructs used or silencing. HaHB11, which presents structural similarities with HaHB4, wasshown as able to confer tolerance to flooding and increased yield in standard growth conditions. It was successfully introduced in maize, rice andsoybean plants. Transgenic maize was assessed during two years in the greenhouse and in field trials showing increased biomass and yield atdifferent extents. Transgenic HaHB11 rice was assessed only during one campaign showing promising results. Altogether, the assays performedwith different transgenic technologies to improve crops performance indicated that once a technology is validated in a model, it is important tochoose a suitable genetic construct and crop to transform and, most important, all the results must be classified as preliminary until repeated fieldtrials are conducted in different environmental conditions.