AUTHOR=Andrade Larissa Mara , Peixoto-Junior Rafael Fávero , Ribeiro Rafael Vasconcelos , Nóbile Paula Macedo , Brito Michael Santos , Marchiori Paulo Eduardo Ribeiro , Carlin Samira Domingues , Martins Alexandre Palma Boer , Goldman Maria Helena S. , Llerena Juan Pablo Portilla , Fregonesi Caroline , Perecin Dilermando , Nebó João Felipe Carlos de Oliveira , Figueira Antonio , Benatti Thiago Romanos , Silva Jorge da , Mazzafera Paulo , Creste Silvana 

TITLE=Biomass Accumulation and Cell Wall Structure of Rice Plants Overexpressing a Dirigent-Jacalin of Sugarcane (ShDJ) Under Varying Conditions of Water Availability

JOURNAL=Frontiers in Plant Science

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00065

DOI=10.3389/fpls.2019.00065

ISSN=1664-462X

ABSTRACT=<p>A sugarcane gene encoding a <italic>dirigent-jacalin</italic>, <italic>ShDJ</italic>, was induced under drought stress. To elucidate its biological function, we integrated a <italic>ShDJ</italic>-overexpression construction into the rice Nipponbare genome via <italic>Agrobacterium</italic>-mediated transformation. Two transgenic lines with a single copy gene in T<sub>0</sub> were selected and evaluated in both the T<sub>1</sub> and T<sub>4</sub> generations. Transgenic lines had drastically improved survival rate under water deficit conditions, at rates close to 100%, while WT did not survive. Besides, transgenic lines had improved biomass production and higher tillering under water deficit conditions compared with WT plants. Reduced pectin and hemicellulose contents were observed in transgenic lines compared with wild-type plants under both well-watered and water deficit conditions, whereas cellulose content was unchanged in line #17 and reduced in line #29 under conditions of low water availability. Changes in lignin content under water deficit were only observed in line #17. However, improvements in saccharification were found in both transgenic lines along with changes in the expression of <italic>OsNTS1/2</italic> and <italic>OsMYB58/63</italic> secondary cell wall biosynthesis genes. <italic>ShDJ</italic>-overexpression up-regulated the expression of the <italic>OsbZIP23</italic>, <italic>OsGRAS23</italic>, <italic>OsP5CS</italic>, and <italic>OsLea3</italic> genes in rice stems under well-watered conditions. Taken together, our data suggest that <italic>ShDJ</italic> has the potential for improving drought tolerance, plant biomass accumulation, and saccharification efficiency.</p>