Perhaps you should try some spelling variations:
"plants disease research." » "plants diseases research.", "plant disease research.", "plant diseases research."
"plant genome research." » "plant genomic research.", "plant genomics research.", "plant some research."
"plant gene research." » "plant gender research.", "plant zone research.", "plant genetic research.", "plant genomes research."
"plants use research." » "plants care research.", "plants used research.", "plants useful research.", "plants under research."
"plant use research." » "plant care research.", "plants used research."

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("plant gene research.") or ("plant genome research."))) or ((("plants disease research.") or ((("plants use research.") OR ("plant use research."))))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("plant gene research.") OR ("plant genome research."))) OR ((("plants disease research.") OR ((("plants use research.") OR ("plant use research.")))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"plant gene research.\") or (\"plant genome research.\"))) or (((\"plants disease research.\") or (((\"plants use research.\") OR (\"plant use research.\"))))))".
• Removing quotes may allow a broader search: (((( plant gene research. ) or ( plant genome research. ))) or ((( plants disease research. ) or ((( plants use research. ) OR ( plant use research. )))))).
• Adding a wildcard symbol may retrieve word variants: (((("plant gene research.") or ("plant genome research."))) or ((("plants disease research.") or ((("plants use research.") OR ("plant use research."))))))*.