Overexpression of the Arabidopsis α-expansin gene AtEXPA1 accelerates stomatal opening by decreasing the volumetric elastic modulus.
Guard cell walls of stomata are highly specialized in plants. Previous research focused on the structure and anatomy of guard cell walls, but little is known about guard cell regulation during stomata movement. In this work, we investigate the possible biological role of the Arabidopsis expansin gene AtEXPA1 in stomatal opening. The AtEXPA1 promoter drove the expression of the GUS reporter gene specifically in guard cells. Light-induced stomatal opening was accelerated in 35S::AtEXPA1 lines, whereas the anti-AtEXPA1 antibody decelerated light-induced stomatal opening. The inhibition of the anti-AtEXPA1 antibody on stomatal opening was largely dependent on the environmental pH. The volumetric elastic modulus (ε) was measured as an indicator of changes in the cell wall. The ε value of guard cells in 35S::AtEXPA1 lines was smaller than in the wild types. The putative role of AtEXPA1 as controller of stomatal opening rate and its regulation are discussed.
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, People's Republic of China.
Xiu-Qing
XQ
Zhang
Peng-Cheng
PC
Wei
Yan-Mei
YM
Xiong
Yi
Y
Yang
Jia
J
Chen
Xue-Chen
XC
Wang
D000906:Antibodies / Q000494:pharmacology; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics* / Q000502:physiology* / Q000528:radiation effects; D015536:Down-Regulation / Q000187:drug effects / Q000528:radiation effects; D055119:Elastic Modulus / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000528:radiation effects; D017343:Genes, Plant / Q000235:genetics*; D006863:Hydrogen-Ion Concentration / Q000187:drug effects / Q000528:radiation effects; D008027:Light; D010940:Plant Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D054046:Plant Stomata / Q000166:cytology / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D030821:Plants, Genetically Modified
D000906:Antibodies; D010940:Plant Proteins; C095825:expansin protein, plant