The sunflower TLDc-containing protein HaOXR2 confers tolerance to oxidative stress and waterlogging when expressed in maize plants

TORTI, PABLO; RAINERI, JESICA; MENCIA, REGINA; CAMPI, MABEL; GONZALEZ, DANIEL H.; WELCHEN, ELINA

PLANT SCIENCE

ELSEVIER IRELAND LTD

Año: 2020 vol. 300 p. 1 - 12

0168-9452

The sunflower ( Helianthus annuus L.) genome encodes six proteins containing aTLDc domain, typical of the eukaryotic OXidation Resistance (OXR) protein family.Expression of sunflower HaOXR2 in Arabidopsis generated plants with increasedrosette diameter, higher number of leaves and increased seed production. Maizeinbred lines expressing HaOXR2 also showed increased total leaf area per plant. Inaddition, heterologous expression of HaOXR2 induced an increase in the oxidativestress tolerance in Arabidopsis and maize. Maize transgenic plants expressingHaOXR2 experienced less oxidative damage and exhibited increased photosyntheticperformance and efficiency than non-transgenic segregant plants after treatment ofleaves with the reactive oxygen species generating compound Paraquat. Expression ofHaOXR2 in maize also improved tolerance to waterlogging. The number of expandedleaves, aerial biomass, and stem height and cross-section area were less affected bywaterlogging in HaOXR2 expressing plants, which also displayed less aerial tissuedamage under these conditions. Transgenic plants also showed an increasedproduction of roots, a typical adaptive stress response. The results show the existenceof functional conservation of OXR proteins in dicot and monocot plants and indicatethat HaOXR2 could be useful to improve plant performance under conditions thatincrease oxidative stress.