Analisis Fungsional Gen-Gen Termutasi pada Padi Mutan Hawara Bunar Melalui Komparasi Sekuen DNA, Prediksi Struktur Protein, dan Ekspresi Gen pada Kondisi Cekaman Kekeringan

Abstract

Perbedaan sekuen pada genom termutasi mempengaruhi regulasi gen dan tingkat toleransi tumbuhan terhadap cekaman kekeringan. Perbedaan sensitifitas diduga karena gen mengalami mutasi pada daerah fungsional dari genomnya. Penelitian ini bertujuan (1) mengidentifikasi kandidat gen-gen toleransi cekaman kekeringan melalui kombinasi identifikasi domain fungsional protein dan profil ekspresi transkriptom terkait kekeringan, (2) memvalidasi kandidat gen-gen terpilih melalui prediksi perubahan struktur protein dan analisis ekspresi gen melalui teknik qRT-PCR. Sekuen gen yang termutasi diintegrasikan dengan daftar gen umum yang mengalami perubahan ekspresi pada kondisi kekeringan melalui hasil meta-analisis transkriptom dan divalidasi dengan teknik qRT-PCR. Hasil penelitian menunjukan kandidat gen termutasi tidak terjadi perubahan fungsi protein meskipun terjadi perubahan beberapa asam amino. Gen Os01t0692100 mengalami peningkatan ekspresi, sedangkan gen Os01t0695700 dan Os10t0502400 mengalami penurunan ekspresi pada tanaman padi mutan sensitif cekaman kekeringan ketika mendapat cekaman kekeringan. Hasil penelitian ini dapat digunakan sebagai acuan dalam perakitan varietas tanaman padi toleran cekaman kekeringan.

Sequence differences in the mutated genome affect gene regulation and plant tolerance levels to drought stress. This study aims (1) to identify candidate drought stress tolerance genes through a combination of identification of protein functional domains and drought-related transcriptome expression profiles and (2) to validate selected candidate genes by predicting changes in protein structure and analyzing gene expression through qRT-PCR techniques. The mutated gene sequences were integrated with a list of common genes that experienced changes in expression under drought conditions through transcriptome meta-analysis and validated by the qRT-PCR technique. The results showed that the mutated candidate gene did not change the protein function even though there was a change in several amino acids. The Os01t0692100 gene experienced an increase in expression, while the Os01t0695700 and Os10t0502400 genes experienced a decreased expression in drought-sensitive mutant rice plant under drought stress. The results of this study can be used as a reference of drought stress-tolerant rice varieties.