AUTHOR=Priatama Ryza A. , Heo Jung , Kim Sung Hoon , Rajendran Sujeevan , Yoon Seoa , Jeong Dong-Hoon , Choo Young-Kug , Bae Jong Hyang , Kim Chul Min , Lee Yeon Hee , Demura Taku , Lee Young Koung , Choi Eun-Young , Han Chang-deok , Park Soon Ju 

TITLE=Narrow lpa1 Metaxylems Enhance Drought Tolerance and Optimize Water Use for Grain Filling in Dwarf Rice

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.894545

DOI=10.3389/fpls.2022.894545

ISSN=1664-462X

ABSTRACT=<p>Rice cultivation needs extensive amounts of water. Moreover, increased frequency of droughts and water scarcity has become a global concern for rice cultivation. Hence, optimization of water use is crucial for sustainable agriculture. Here, we characterized <italic>Loose Plant Architecture 1</italic> (<italic>LPA1</italic>) in vasculature development, water transport, drought resistance, and grain yield. We performed genetic combination of <italic>lpa1</italic> with semi-dwarf mutant to offer the optimum rice architecture for more efficient water use. <italic>LPA1</italic> expressed in pre-vascular cells of leaf primordia regulates genes associated with carbohydrate metabolism and cell enlargement. Thus, it plays a role in metaxylem enlargement of the aerial organs. Narrow metaxylem of <italic>lpa1</italic> exhibit leaves curling on sunny day and convey drought tolerance but reduce grain yield in mature plants. However, the genetic combination of <italic>lpa1</italic> with semi-dwarf mutant (<italic>dep1-ko</italic> or <italic>d2</italic>) offer optimal water supply and drought resistance without impacting grain-filling rates. Our results show that water use, and transports can be genetically controlled by optimizing metaxylem vessel size and plant height, which may be utilized for enhancing drought tolerance and offers the potential solution to face the more frequent harsh climate condition in the future.</p>