ZmIAA5 regulates maize root growth and development by interacting with ZmARF5 under the specific binding of ZmTCP15/16/17

Abstract

Background The auxin indole-3-acetic acid (IAA) is a type of endogenous plant hormone with a low concentration in plants, but it plays an important role in their growth and development. The AUX/IAA gene family was found to be an early sensitive auxin gene with a complicated way of regulating growth and development in plants. The regulation of root growth and development by AUX/IAA family genes has been reported in Arabidopsis, rice and maize. Results In this study, subcellular localization indicated that ZmIAA1-ZmIAA6 primarily played a role in the nucleus. A thermogram analysis showed that AUX/IAA genes were highly expressed in the roots, which was also confirmed by the maize tissue expression patterns. In maize overexpressing ZmIAA5, the length of the main root, the number of lateral roots, and the stalk height at the seedling stage were significantly increased compared with those of the wild type, while the EMS mutant zmiaa5 was significantly reduced. The total number of roots and the dry weight of maize overexpressing ZmIAA5 at the mature stage were also significantly increased compared with those of the wild type, while those of the mutant zmiaa5 was significantly reduced. Yeast one-hybrid experiments showed that ZmTCP15/16/17 could specifically bind to the ZmIAA5 promoter region. Bimolecular fluorescence complementation and yeast two-hybridization indicated an interaction between ZmIAA5 and ZmARF5. Conclusions Taken together, the results of this study indicate that ZmIAA5 regulates maize root growth and development by interacting with ZmARF5 under the specific binding of ZmTCP15/16/17.

ZmLLG1 gene affects the development of the maize root system

“…The functions of 15 of the 29 Aux/IAA gene families in Arabidopsis have been clearly reported (Yang F et al, 2022). For example, Arabidopsis plants with the acquired mutant iaa8, of the Aux/IAA gene family, were found to have shorter heights, loss of apical dominance, frizzled leaves, and abnormal flower organ development (Reed JW, 2001).…”

“…Multiple studies have shown that AUX/IAA proteins and auxin-responsive factor (ARF) mediated signaling play an important role in regulating plant root formation (Yang F et al,2022). ZmIAA10 can interact with ZmARF25 and ZmARF34, thereby affecting root growth and development in maize (Deng et al, 2014).…”

“…The seeds of the maize B73 inbred lines and mutant zmllg1 seeds were sterilized, washed using distilled water and then sown in a tray of vermiculite saturated with water. When the maize seedlings reached the three-leaf stage, they were transferred to Hoagland liquid medium (Table S2) for approximately eight days, and then the maize root system was measured and recorded (Yang F et al, 2022). To investigate the expression changes of ZmLLG1 under different auxin stress treatments, when the B73 maize seedlings reached the three-leaf stage, they were transferred to Hoagland liquid medium containing 0.3 μM NAA and 5 μM NAA, respectively.…”

“…In order to study the maize mutant zmllg1, we ordered two zmllg1 maize mutants, zmllg1-1 and zmllg1-2, from the mutant library website (http://www.elabcaas.cn/memd) These mutants were created by the EMS chemical mutagenesis of the maize B73 inbred line (Yang F et al, 2022). The mutation was located at the 849 bp position on the second exon, which changed the original cytosine (C) to thymidine (T).…”

“…The AD and BD fusion constructs were co-transformed into the yeast strain Gold2 system to test their interactions and cultured on SD/-Trp-Leu-His-Ade deficient solid medium at 29 °C for two to three days . The plaque growth was observed, and positive and negative controls were established (Yang F et al, 2022).…”