Natural variation of Alfin‐like family affects seed size and drought tolerance in rice

Abstract

SUMMARY The Alfin‐like (AL) family is a group of small plant‐specific transcriptional factors involved in abiotic stresses in dicotyledon. In an early study, we found an AL gene in rice that was associated with grain yield under drought stress. However, little information is known about the AL family in rice. In this study, AL genes in the rice genome were identified, and the OsAL proteins were found to locate in the nucleus and have no transcriptional self‐activation activity. The expression of the OsALs was regulated by different environmental stimulations and plant hormones. Association and domestication analysis revealed that natural variation of most OsALs was significantly associated with yield traits, drought resistance and divergence in grain size in indica and japonica rice varieties. Hap1 of OsAL7.1 and Hap7 of OsAL11 were favorable haplotypes of seed weight and germination under osmotic stress. Furthermore, osal7.1 and osal11 mutants have larger seeds and are more sensitive to abscisic acid and mannitol during germination stage. Overexpressing of OsAL7.1 and OsAL11 in rice weakened the tolerance to drought in the adult stage. Thus, our work provides informative knowledge for exploring and harnessing haplotype diversity of OsALs to improve yield stability under drought stress.

The Alfin-like transcription factor GmAlfin09 regulates endoplasmic reticulum stress in soybean via a peroxidase GmPRDX6

“…and OsAL11 exhibited poorer drought tolerance (Yang et al, 2022). Seven total AL proteins have been reported in Arabidopsis.…”

“…For example, of the four AhAL genes identified in spinach, only AhAL1 enhanced the salt and drought tolerance of Arabidopsis when constitutively expressed, whereas the other three increased Arabidopsis sensitivity to salt stress, highlighting clear functional differences among the members of this AhAL protein family (Tao et al, 2018). Similarly, adult-stage rice plants overexpressing OsAL7.1 and OsAL11 exhibited poorer drought tolerance (Yang et al, 2022). Seven total AL proteins have been reported in Arabidopsis.…”

Prospects for rice in 2050

“…With the rapid advances in whole genome sequencing technology and genome‐wide association study (GWAS) analysis, we have witnessed great progress in elucidating the natural variation underpinning agronomic traits and the underlying genetic architectures in rice. For example, HAN1 (Mao et al, 2019) and COLD11 (Li, Zhang, Yang, et al, 2022) for chilling tolerance, OsALs (Alfin‐like family genes) for seed size and drought tolerance (Y. Yang, Ma, et al, 2022), OsLG3 (an ERF family TF) for drought tolerance (Xiong et al, 2018), DRO1 for saline tolerance (Kitomi et al, 2020), and NOMT (a naringenin 7‐O‐methyltransferase) for resistant to fungal diseases (Murata et al, 2020). In this issue, Hong, Rosental, et al (2023) profiled glycerolipids in seeds of 587 Asian cultivated rice accessions and 103 chromosomal segment substitution lines, and revealed their significant natural variation in rice.…”

Molecular Network for Regulation of Seed Size in Plants

“…The Alfin-like (AL) family is a group of small plant-specific transcriptional factors, and null mutants of the rice OsAl7.1 and OsAl11 have increased seed size [ 55 ]. ATBS-INTERACTING FACTOR 2 (AIF2) is a non-DNA-binding basic helix–loop–helix (bHLH) transcription factor [ 56 ].…”